Medical dictionary

Medical dictionary

A Medical dictionary is a specialized dictionary that contains words and phrases related to the field of medicine. It is a valuable resource for medical professionals, students, and anyone interested in understanding medical terminology.

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Pronunciation

Medical dictionary (med-i-kal dik-shuh-ner-ee)

Etymology

The term "medical dictionary" is derived from the Latin word "medicus" meaning "physician" and the English word "dictionary" which originates from the Latin "dictionarium," meaning "collection of words."

Description

A medical dictionary provides definitions, explanations, and descriptions of medical terms. It may also include information about the etymology of words, their pronunciation, and their use in context. Some medical dictionaries also provide information about related terms, synonyms, and antonyms.

Types of Medical Dictionaries

There are several types of medical dictionaries, including general medical dictionaries, specialized medical dictionaries, and multilingual medical dictionaries.

• General Medical Dictionaries: These dictionaries cover a wide range of medical terms from various medical fields. They are often used by medical students and professionals as a reference tool.

• Specialized Medical Dictionaries: These dictionaries focus on a specific area of medicine, such as cardiology, neurology, or oncology. They are often used by specialists in these fields.

• Multilingual Medical Dictionaries: These dictionaries provide translations of medical terms in multiple languages. They are often used by medical professionals who work in multilingual environments or by patients who speak different languages.

Importance of Medical Dictionaries

Medical dictionaries are essential tools in the field of medicine. They help medical professionals communicate effectively and accurately. They also help students learn and understand medical terminology. Furthermore, they can be useful for patients who want to understand their medical conditions and treatments better.

Below is a list of sample articles that cover a broad range of important topics in medicine. Each entry is linked internally, allowing for easy navigation and exploration within our dictionary.

• Alternative Medicine: Explore the diverse world of healing practices outside mainstream medical science, including herbal remedies, acupuncture, and more.
• Molecular oncology: Dive into the molecular basis of cancer, understanding how genetic mutations lead to the disease and the development of targeted therapies.
• Nanomedicine: Discover how nanotechnology is revolutionizing medicine, from drug delivery systems to diagnostic tools.
• Personalized medicine: Understand how genetic information is used to tailor medical treatment to the individual patient for better outcomes.
• Public Health: Explore the science and practice of protecting and improving the health of communities through education, policy-making, and research for disease and injury prevention.
• Rural health: Learn about the unique challenges and solutions in providing healthcare to rural populations.
• Therapy: Delve into the various therapeutic interventions used to treat illness and promote health, from physical therapy to psychotherapy.
• Traditional Medicine: Gain insight into the healing practices and beliefs that have been passed down through generations, often forming the backbone of community healthcare.
• Veterinary medicine: Explore the medical care and treatment of animals, encompassing a wide range of species from household pets to livestock and wildlife.
• Physician and Chief physician: Understand the roles and responsibilities of medical doctors, including the leadership role of chief physicians in healthcare settings.
• Specific Conditions and Treatments:
• Acne, Alcoholism, Diabetes, Fibromyalgia, and Psoriasis: Articles on common conditions, their causes, and treatments.
• Acyclovir, Alprazolam, Zolpidem, Antioxidant, Ativan, and Cialis: Information on specific medications, their uses, and effects.
• Addiction, Anxiety, Detoxification, Drug, Health care, and Medication: Broader topics addressing mental health issues, substance abuse, and the healthcare system.
• Dental, Pharmacy, Prescription, and Psychic: Explore areas related to dental health, pharmaceuticals, prescribing practices, and the impact of mental health on physical health.

Common medical terms - glossary

This glossary provides definitions and links to further information for key terms in medicine, starting with the letter A.

A

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• Abdomen - The part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates.
• Abdominal cavity - The largest cavity in the body housing the stomach, liver, gallbladder, spleen, pancreas, small intestine, kidneys, and more.
• Abdominal distention - The condition of being distended or swollen in the abdominal area, often due to gas, fluid, or enlargement of organs.
• Abscess - A collection of pus that has built up within the tissue of the body, often caused by an infection.
• Accommodation (eye) - The process by which the eye changes optical power to maintain a clear image or focus on an object as its distance varies.
• Accommodation reflex - A reflex action of the eye, responding to focusing on a near object, then looking at a distant object (and vice versa), comprising changes in vergence, lens shape, and pupil size.
• Acetabulum - The concave surface of the pelvis that receives the femur (thigh bone), forming the hip joint.
• Achilles tendon - A tendon of the back of the leg, and the thickest in the human body, that attaches the calf muscles to the heel bone.
• Acid - A molecule or ion capable of donating a proton (hydrogen ion H+), or, alternatively, capable of forming a covalent bond with an electron pair (a Lewis acid).
• Acne - A skin condition that occurs when hair follicles become plugged with oil and dead skin cells, leading to whiteheads, blackheads, or pimples.
• Acquired immunity - Immunity that develops after exposure to a disease agent or vaccination.
• Action potential - A rapid rise and subsequent fall in voltage or membrane potential across a cellular membrane with a characteristic pattern.
• Acupressure - An alternative medicine technique similar in principle to acupuncture, involving the application of pressure to specific points on the body.
• Acupuncture - A form of alternative medicine and a key component of traditional Chinese medicine involving thin needles inserted into the body at acupuncture points.
• Acute (medicine) - Describing a disease of rapid onset, severe symptoms, and brief duration, opposite of chronic.
• Adam's apple - The lump or protrusion in the throat formed by the angle of the thyroid cartilage surrounding the larynx visible especially in males.
• Adaptive immune system - The part of the immune system that is composed of specialized, systemic cells and processes that eliminate pathogens or prevent their growth.
• Adductor hiatus - An opening in the adductor magnus muscle of the thigh that allows passage of the femoral artery into the popliteal fossa.
• Adductor magnus - A large, triangular muscle, situated on the medial side of the thigh, that is involved in adduction of the thigh.
• Adenoids - A mass of lymphatic tissue in the nasopharynx, similar to the tonsils, often removed when enlarged and causing health problems.
• Adenoma - A type of noncancerous tumor or benign tumor that may affect various organs.
• Adrenal gland - Endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys.
• Adrenaline - A hormone and a medication which is involved in regulation of the "fight or flight" response.
• Aedes - A genus of mosquitoes originally found in tropical and subtropical zones, but now found on all continents except Antarctica.
• Aedes aegypti - A species of mosquito that is a known vector for several viruses including yellow fever virus, dengue virus, chikungunya virus, and Zika virus.
• Aedes albopictus - Also known as the Asian tiger mosquito, a vector known to transmit diseases like dengue fever, chikungunya, and Zika fever.
• Afferent nerve fiber - Nerve fibers that carry sensory signals from the body to the central nervous system.
• Age appropriateness - The consideration of whether content or activities are suitable for someone's age group and development level.
• Aging - The process of becoming older, a natural part of life with physiological changes that lead to decline of biological functions and of the organism's ability to adapt to metabolic stress.
• Agriculture - The science, art, and practice of cultivating plants and livestock.
• Airway obstruction - A blockage in any part of the airway that prevents air from getting into the lungs, leading to breathing difficulties.
• Alcohol (drug) - An organic compound used in beverages and as a solvent and antiseptic; ethyl alcohol or ethanol is the type consumed in alcoholic beverages.
• Aldosterone - A steroid hormone produced by the adrenal cortex that regulates salt and water balance in the body.
• Alimentary canal - The whole passage along which food passes through the body from mouth to anus, including the esophagus, stomach, and intestines.
• Allergic asthma - A type of asthma triggered by allergens such as pollen, dust mites, mold spores, or pet dander.
• Allergic conjunctivitis - Inflammation of the conjunctiva of the eye caused by allergic reactions.
• Allergy - An immune system response to a foreign substance that's not typically harmful to your body.
• Allied health professions - Professions in health care distinct from nursing, medicine, and pharmacy. They provide a range of diagnostic, technical, therapeutic, and support services.
• Alpha-keratin - A type of keratin found in vertebrates, forming the hair, the outer layer of the skin, and nails.
• Alternative medicine - Practices claimed to have the healing effects of medicine but not based on evidence gathered using the scientific method.
• Alzheimer's disease - A chronic neurodegenerative disease that usually starts slowly and progressively worsens, being the most common cause of dementia.
• American English - The set of varieties of the English language native to the United States.
• Amino acids - Organic compounds that combine to form proteins, serving as the building blocks of life.
• Amnesia - A partial or total loss of memory.
• Amsler grid - A grid used by eye health professionals to detect vision problems resulting from damage to the macula (the central part of the retina) or the optic nerve.
• Anal canal - The terminal part of the large intestine, situated between the rectum and anus.
• Anal triangle - The region of the perineum bounded by the thighs and the buttocks, containing the anus and, in females, the vaginal opening.
• Anal verge - The area of the anal canal that is directly visible from the exterior of the body.
• Anaphylaxis - A severe, potentially life-threatening allergic reaction.
• Anatomical snuff box - A triangular deepening on the radial, dorsal aspect of the hand—at the level of the carpal bones, specifically the scaphoid and trapezium bones formed by the tendons of the thumb.
• Anatomical terms of motion - Terms used to describe motion, taken from the Latin and Greek languages, used in medicine and physiology.
• Anatomical terms of muscle - Terms used to describe muscle actions, taken from Latin and Greek languages.
• Anatomy - The branch of biology concerned with the study of the structure of organisms and their parts.
• Andrology - The medical specialty that deals with male health, particularly relating to the problems of the male reproductive system and urological problems that are unique to men.
• Anesthesiology - The medical specialty concerned with the total perioperative care of patients before, during, and after surgery. It encompasses anesthesia, intensive care medicine, critical emergency medicine, and pain medicine.
• Angina pectoris - A type of chest pain caused by reduced blood flow to the heart.
• Angiology - The medical specialty which studies the diseases of the circulatory system and of the lymphatic system, i.e., arteries, veins, and lymphatic vases, and its diseases.
• Anhedonia - The inability to feel pleasure in normally pleasurable activities.
• Animal - A multicellular eukaryotic organism that is characterized by being motile, at some point in their lives, and being heterotrophs that eat other organisms or parts of them.
• Animal locomotion - Any of a variety of movements or methods that animals use to move from one place to another.
• Ankle - The region where the foot and the leg meet.
• Annulus of Zinn - A ring of fibrous tissue surrounding the optic nerve at its entrance at the apex of the orbit.
• Anorexia (symptom) - Loss of appetite for food, which can be a symptom of diseases such as cancer, AIDS, and some neurological conditions.
• Antecubital fossa - The triangular area on the anterior view of the elbow of a human or other hominid animal, including many primates.
• Anterior - An anatomical term of location that indicates something situated towards the front of the body, opposed to posterior.
• Anterior nasal spine - A bony projection in the skull that serves as a cephalometric landmark.
• Anterior tibial artery - One of the most important arteries of the lower leg, supplying blood to the anterior compartment of the leg and dorsal surface of the foot.
• Antibiotic - A type of antimicrobial substance active against bacteria.
• Antibiotic prophylaxis - The prevention of bacterial infection by the administration of antibiotics before a surgery or procedure.
• Antibody - A large, Y-shaped protein produced mainly by plasma cells that is used by the immune system to neutralize pathogens such as pathogenic bacteria and viruses.
• Antimicrobial - An agent that kills microorganisms or stops their growth.
• Anus - The opening at the end of the digestive tract from which feces exit the body.
• Aorta - The largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries (the common iliac arteries).
• Aortic aneurysm - An enlargement (dilation) of the aorta to greater than 1.5 times normal size.
• Aortic bifurcation - The point at which the aorta branches into the two common iliac arteries in the lower abdomen.
• Aponeurosis - A type of fibrous tissue that takes the place of a tendon in sheetlike muscles having a wide area of attachment.
• Appendix (anatomy) - A tube-shaped sac attached to and opening into the lower end of the large intestine in humans and some other mammals. In humans, the appendix is considered to be a part of the gut-associated lymphoid tissue.
• Aqueous humor - A transparent, watery fluid similar to plasma, but containing low protein concentrations, found in the anterior and posterior chambers of the eye.
• Arm - The part of the upper limb between the shoulder and the elbow.
• Arteries - Blood vessels that carry blood away from the heart to all parts of the body (tissues, lungs, brain, etc.).
• Arteriole - A small-diameter blood vessel in the microcirculation that extends and branches out from an artery and leads to capillaries.
• Artery - A blood vessel that takes blood away from the heart to all parts of the body (tissues, lungs, etc.).
• Arthritis - Inflammation of one or more joints, causing pain and stiffness that can worsen with age.
• Articulation (anatomy) - A joint or the collection of joints at which a human or an animal body moves.
• Asperger syndrome - A developmental disorder characterized by significant difficulties in social interaction and nonverbal communication, along with restricted and repetitive patterns of behavior and interests.
• Assimilation (biology) - The process by which a living organism assimilates food and uses it for growth and for replacement of tissues.
• Asthma - A common long-term inflammatory disease of the airways of the lungs, characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms.
• Asymptomatic - Showing no symptoms or signs of infection.
• Ataxia - A neurological sign consisting of lack of voluntary coordination of muscle movements that includes gait abnormality.
• Atherosclerosis - A disease in which the inside of an artery narrows due to the build-up of plaque.
• Athletic training - A profession that involves preventing, diagnosing, and treating muscle and bone injuries and illnesses.
• Atmospheric pressure - The pressure within the atmosphere of Earth. Standard atmosphere (symbolatm) is a unit of pressure defined as 101325 Pa.
• Atopic dermatitis - A type of inflammation of the skin (dermatitis) that results in itchy, red, swollen, and cracked skin.
• Atrial fibrillation - An abnormal heart rhythm characterized by rapid and irregular beating of the atria.
• Atrium (heart) - The two upper cavities of the heart from which blood is passed to the ventricles. The right atrium receives deoxygenated blood from the veins of the body; the left atrium receives oxygenated blood from the pulmonary vein.
• Attending physician - A doctor who has completed residency and practices medicine in a clinic or hospital, in the specialty learned during residency.
• Attention - The behavioral and cognitive process of selectively concentrating on a discrete aspect of information, whether deemed subjective or objective, while ignoring other perceivable information.
• Audiology - The branch of science that studies hearing, balance, and related disorders.
• Auricle (anatomy) - The visible part of the ear that is outside the head.
• Auscultation - Listening to the internal sounds of the body, usually using a stethoscope.
• Australia - A country comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands.
• Autism - A developmental disorder characterized by difficulties with social interaction and communication, and by restricted and repetitive behavior.
• Autism spectrum - The range of neurodevelopmental disorders comprising autism and related conditions.
• Autoimmune disease - A condition arising from an abnormal immune response to a normal body part.
• Autoimmune disorder - Any of a large group of diseases characterized by a condition in which the immune system produces antibodies against its own tissues.
• Autonomic nervous system - The part of the nervous system responsible for control of the bodily functions not consciously directed, such as breathing, the heartbeat, and digestive processes.
• Axilla - The area of the human body directly under the joint where the arm connects to the shoulder.
• Axillary artery - A large blood vessel that conveys blood from the lateral edge of the first rib to the teres major muscle.
• Axillary vein - A large blood vessel that conveys blood from the lateral aspect of the thorax, axilla, and upper limb toward the heart.
• Axon - A long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body.

B

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• Back: The rear surface of the human body from the shoulders to the hips.
• Back pain: Discomfort or pain located in the back area, often caused by muscle strains, spinal problems, or nerve issues.
• Bacteria: Microscopic, single-celled organisms that thrive in diverse environments and can have health-related effects ranging from beneficial to harmful.
• Bacterium: Singular form of bacteria, referring to a single bacterial cell.
• Barotrauma: Physical damage to body tissues caused by a difference in pressure between an air space inside or beside the body and the surrounding fluid.
• Basal ganglia: A group of nuclei in the brain associated with a variety of functions, including control of voluntary motor movements, procedural learning, and emotions.
• Basal metabolic rate (BMR): The rate of energy expenditure per unit time by endothermic animals at rest, representing the minimum amount of energy needed to keep the body functioning, including breathing and keeping warm.
• Base of skull: The bottom part of the skull, composed of the occipital bone, temporal bones, sphenoid bone, and parts of the parietal and ethmoid bones.
• Basic research: Fundamental scientific research aimed at increasing understanding of fundamental principles, without immediate commercial goals but with long-term benefits to society.
• Basilic vein: A large superficial vein of the upper limb that helps drain parts of the hand and forearm.
• Behavior: The range of actions and mannerisms made by individuals, organisms, systems, or artificial entities in conjunction with themselves or their environment.
• Benign tumor: A non-cancerous growth that does not invade nearby tissues or spread to other parts of the body.
• Beta cell: A type of cell in the pancreas located in the islets of Langerhans, which produces and releases insulin.
• Bicarbonate: A bicarbonate ion (HCO3−) or a compound containing it, playing a critical role in maintaining pH balance in the body.
• Biceps: A large muscle in the upper arm that turns the hand to face palm uppermost and flexes the arm and forearm.
• Biceps brachii muscle: The full name of the biceps, highlighting its two heads (long and short) that originate from the scapula and insert into the radius.
• Bile: A digestive fluid produced by the liver and stored in the gallbladder, aiding in the digestion of lipids in the small intestine.
• Bile acid: Components of bile, which are steroidal acids produced by the liver and are crucial for digestion and absorption of fats.
• Bile duct: Ducts that convey bile from the liver and the gallbladder to the duodenum.
• Bile ducts: The network of thin tubes that transport bile from the liver and gallbladder into the small intestine.
• Biliary tract: The system of organs and ducts that create, store, and transport bile.
• Bilirubin: A yellow compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates, causing the yellow color of bruises and the yellow discoloration in jaundice.
• Binge eating: The consumption of large quantities of food in a short period of time, often associated with a feeling of loss of control.
• Binge eating disorder: A disorder characterized by recurrent episodes of binge eating without the regular use of compensatory measures to counter the binge eating.
• Biochemistry: The study of chemical processes within and relating to living organisms.
• Bioinformatics: An interdisciplinary field that develops methods and software tools for understanding biological data, particularly when the data sets are large and complex.
• Biological engineering: An interdisciplinary area focusing on the application of engineering principles to analyze biological systems and to solve problems in the intersection of biological and engineering fields.
• Biological life cycle: The sequence of life stages that an organism undergoes from birth to reproduction ending with the generation of the offspring.
• Biological process: Processes vital for a living organism to live, and that shape its capacities for interacting with its environment.
• Biological system: A complex network of biologically relevant entities or processes.
• Biological tissue: Groups of cells that perform a similar function and are the materials of which animals and plants are made.
• Biology: The natural science that studies life and living organisms, including their physical structure, chemical processes, molecular interactions, physiological mechanisms, development, and evolution.
• Biopsy: A medical test commonly performed by a surgeon, interventional radiologist, or an interventional cardiologist involving extraction of sample cells or tissues for examination to determine the presence or extent of a disease.
• Biostatistics: The application of statistics to a wide range of topics in biology.
• Biosynthesis: The multi-step, enzyme-catalyzed process by which the simple substances are converted into more complex products in living organisms.
• Bipolar disorder: A mental disorder marked by periods of depression and periods of elevated mood.
• Birds: Warm-blooded vertebrates of the class Aves, distinguished by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton.
• Birth: The process of giving birth to offspring, marking the beginning of a new individual's life outside the mother's womb.
• Birth control: Methods or devices used to prevent pregnancy.
• Bladder: An organ that collects urine excreted by the kidneys before disposal by urination.
• Bladder cancer: A common type of cancer that begins in the cells of the bladder.
• Blisters: Small pockets of body fluid (lymph, serum, plasma, blood, or pus) within the upper layers of the skin, typically caused by forceful rubbing (friction), burning, freezing, chemical exposure, or infection.
• Blood: A body fluid in humans and other animals that delivers necessary substances such as nutrients and oxygen to the cells and transports metabolic waste products away from those same cells.
• Blood cell: Cells found in blood, including red blood cells, white blood cells, and platelets.
• Blood pressure: The pressure of circulating blood on the walls of blood vessels, an important parameter in assessing health status.
• Blood sugar level: The amount of glucose present in the blood, an important indicator of metabolic health and regulation.
• Blood vessel: A tubular structure carrying blood through the tissues and organs; a vein, artery, or capillary.
• Body of the femur: The long, straight part of the femur or thigh bone.
• Body plan: The blueprint for the way the body of an organism is laid out, including its symmetry, segmentation, and limb disposition.
• Body temperature: The measure of the body's ability to generate and get rid of heat, a vital parameter for metabolic functioning.
• Bone: A rigid organ that constitutes part of the vertebral skeleton, supporting and protecting various organs of the body.
• Bone fracture: A medical condition in which there is a partial or complete break in the continuity of the bone.
• Bone marrow: The soft, fatty substance in the cavities of bones, where blood cell production occurs.
• Bone pain: Discomfort, aching, or tenderness in one or more bones, often associated with diseases such as osteoporosis or cancer.
• Bony fish: Fish that have skeletons primarily composed of bone tissue, as opposed to cartilaginous fish, which have skeletons made of cartilage.
• Bony labyrinth: A complex system of passages and cavities within the temporal bone of the skull, involved in the sense of balance and hearing.
• Brachial artery: The major blood vessel of the (upper) arm, continuing from the axillary artery, down to the elbow, where it splits into the radial and ulnar arteries.
• Brachial plexus: A network of nerves formed by the ventral rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1), responsible for sensory and motor supply to the upper limb.
• Brachial veins: Veins accompanying the brachial artery and draining the arm.
• Brachioradialis: A muscle of the forearm that flexes the forearm at the elbow.
• Bradycardia: An abnormally slow heart rate, typically defined as a heart rate under 60 beats per minute in adults.
• Brain: The organ of the central nervous system of vertebrates located in the head, responsible for coordination of sensation, intellectual and nervous activity.
• Brain metastasis: Cancer cells that have spread to the brain from primary tumors in other organs.
• Brain tumor: An abnormal growth of cells within the brain, which can be cancerous or non-cancerous (benign).
• Brain tumour: Alternate spelling of brain tumor, referring to the same condition.
• Brainstem: The posterior part of the brain, adjoining and structurally continuous with the spinal cord, responsible for basic vital life functions such as breathing, heartbeat, and blood pressure.
• Breast: The upper ventral region of the torso of a primate, in females it contains the mammary gland, which can produce milk to feed infants.
• Breast cancer: A disease in which cells in the breast tissue divide and grow without normal control.
• Breast development: The process of maturation that produces adult breasts, a key feature of female puberty.
• Breast lump: A localized swelling, protuberance, bulge, or bump in the breast that feels different from the breast tissue around it or the breast tissue in the same area of the other breast.
• Broca's area: A region in the frontal lobe of the dominant hemisphere of the hominid brain with functions linked to speech production.
• Brodmann area: Regions of the cerebral cortex defined based on their cytoarchitectonic characteristics.
• Brodmann area 18: Associated with the processing of visual information.
• Brodmann area 19: Involved in visual processing, including the processing of motion and color.
• Brodmann area 22: Involved in the comprehension of speech and is part of Wernicke's area.
• Bronchi: The main passageways directly attached to the lungs that allow air to move in and out of the lungs.
• Bronchial tubes: The larger tubes that lead from the trachea to the lungs, branching into smaller tubes called bronchioles.
• Bronchiole: Any of the minute branches into which a bronchus divides.
• Bronchospasm: A sudden constriction of the muscles in the walls of the bronchioles, causing difficulty in breathing.
• Bronchus: Either of the two main branches of the trachea that lead directly to the lungs.
• Bruit: A sound, usually abnormal, heard in auscultation.
• Buccal nerve: A nerve in the face that is a branch of the mandibular nerve, part of the trigeminal nerve, providing sensory innervation to the cheek.
• Bulimia nervosa: An eating disorder characterized by binge eating followed by purging.
• Buttock: The posterior part of the human pelvis, often referred to in the plural as the buttocks.
• Buttocks: The two rounded portions of the anatomy, located on the posterior of the pelvic region of humans and many other bipeds or quadrupeds.

C

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• Calcaneus: The large bone forming the heel of the foot.
• Calcium: A chemical element vital for cellular processes, bone structure, and signaling in the body.
• Calcium in biology: The role of calcium ions in cellular processes and biological functions.
• Calf (leg): The back portion of the lower leg.
• Calf muscle: The muscle group in the back of the lower leg, primarily the gastrocnemius and soleus muscles.
• Caliber: The internal diameter or bore of a tube, often referring to blood vessels or other tubular organs.
• Canada: A country in North America, known for its healthcare system and medical research contributions.
• Cancer: A group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body.
• Cancer cell: A cell that has undergone malignant transformation leading to cancer.
• Cancer vaccine: A vaccine designed to prevent or treat cancer by stimulating the immune system.
• Cancerous: Referring to cells or tissues that are malignant or characteristic of cancer.
• Capillary: Small blood vessels that connect arterioles and venules, facilitating the exchange of water, oxygen, carbon dioxide, and many other nutrients and waste substances between blood and tissues.
• Carbohydrates: Organic compounds consisting of carbon, hydrogen, and oxygen, serving as a major energy source in the diet of animals.
• Carbon dioxide: A colorless gas produced by burning carbon and organic compounds and by respiration, absorbed by plants in photosynthesis.
• Carcinogen: Any substance or agent that promotes the formation of cancer.
• Carcinogenesis: The process by which normal cells are transformed into cancer cells.
• Cardiac arrest: A sudden loss of blood flow resulting from the failure of the heart to effectively pump.
• Cardiac catheterization: A medical procedure used to diagnose and treat some cardiovascular conditions by inserting a catheter into a chamber or vessel of the heart.
• Cardiac cycle: The sequence of events that occur when the heart beats, including the contraction and relaxation of the atria and ventricles.
• Cardiac muscle: Specialized muscle tissue found only in the heart, responsible for pumping blood throughout the body.
• Cardiac muscle cell: A cell that makes up the cardiac muscle, capable of automaticity and rhythmic contraction.
• Cardiac surgery: Surgery on the heart or great vessels performed by cardiac surgeons.
• Cardiology: The branch of medicine dealing with disorders of the heart and blood vessels.
• Cardiomyopathy: A group of diseases that affect the heart muscle, making it harder for the heart to pump blood to the rest of the body.
• Cardiothoracic surgery: The field of medicine involved in surgical treatment of organs inside the thorax (the chest)—primarily the heart and lungs.
• Cardiovascular disease: A class of diseases that involve the heart or blood vessels, including coronary artery disease, hypertension, heart failure, and more.
• Carditis: Inflammation of the heart that can involve the endocardium, myocardium, and/or pericardium.
• Carotid artery: Major arteries in the neck that supply blood to the brain, neck, and face.
• Carotid artery stenosis: Narrowing of the carotid arteries, often due to atherosclerosis, leading to reduced blood flow to the brain.
• Carpal bones: The eight small bones that make up the wrist, allowing it to move and providing support to the hand.
• Carpal tunnel: A narrow passageway in the wrist, surrounded by bones and ligaments, through which the median nerve and tendons pass.
• Carpal tunnel syndrome: A condition caused by compression of the median nerve as it travels through the carpal tunnel, leading to pain, numbness, and tingling in the hand and arm.
• Cartilage: A resilient and smooth elastic tissue, rubber-like padding that covers and protects the ends of long bones at the joints, and is a structural component of the rib cage, the ear, the nose, the bronchial tubes, the intervertebral discs, and many other body components.
• Cartilaginous joint: A type of joint where the bones are entirely joined by cartilage, allowing more movement than a fibrous joint but less than the highly mobile synovial joint.
• Catabolism: The breakdown of complex molecules in living organisms to form simpler ones, together with the release of energy; destructive metabolism.
• Catheter: A thin tube made from medical grade materials serving a broad range of functions, commonly inserted into a body cavity, duct, or vessel.
• Cecum: A pouch connected to the junction of the small and large intestines.
• Cell-mediated immunity: An immune response that does not involve antibodies but rather involves the activation of phagocytes, antigen-specific cytotoxic T-lymphocytes, and the release of various cytokines in response to an antigen.
• Cell (biology): The smallest structural and functional unit of an organism, typically microscopic and consisting of cytoplasm and a nucleus enclosed in a membrane.
• Cell biology: The study of cells' physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division, and death.
• Cell growth: The process by which a cell increases in size or changes in form, often in preparation for cell division.
• Cell membranes: Biological membranes that separate and protect the interior of all cells from the outside environment.
• Cell signaling: The system of communication that governs basic activities of cells and coordinates cell actions.
• Central nervous system (CNS): The part of the nervous system consisting of the brain and spinal cord.
• Cephalic vein: A superficial vein in the arm that provides a route for venous return from the lateral aspect of the arm to the axillary vein and then to the heart.
• Cerebellum: A major structure of the hindbrain that is located near the brainstem and is responsible for motor movements, balance, and coordination.
• Cerebral circulation: The movement of blood through a network of cerebral arteries and veins supplying the brain.
• Cerebral cortex: The outer layer of the cerebrum, composed of folded grey matter and playing an important role in consciousness.
• Cerebral hemisphere: One of the two symmetrical halves of the brain, the left and the right hemispheres, each controlling the opposite side of the body.
• Cerebral hemispheres: The plural form referring to both halves of the brain.
• Cerebrum: The largest part of the brain, containing the cerebral cortex (among other structures), and responsible for most voluntary activities, language, sensory perception, and learning.
• Cervical canal: The spindle-shaped, flattened canal of the cervix, the neck of the uterus.
• Cervical cancer: A malignant tumor of the cervix, the lowermost part of the uterus.
• Cervical spinal nerve 5: The spinal nerve of the cervical segment that supplies the deltoid, biceps, and brachialis muscles.
• Cervical spinal nerve 6: A nerve that provides motor and sensory function to the wrist extensors and the biceps.
• Cervical spinal nerve 7: The nerve that supplies the triceps muscle and is involved in extending the arm at the elbow.
• Cervical spinal nerve 8: A nerve that contributes to the innervation of the lower arm and hand.
• Cervical vertebrae: The seven vertebrae of the spine located in the neck.
• Cervicoaxillary canal: An anatomical passage that runs from the neck to the axilla, bordered by muscles and bones, through which nerves and vessels pass.
• Cervix: The lower part of the uterus in the female reproductive system, connecting the body of the uterus to the vagina.
• Cheek: The fleshy part of either side of the face below the eye and between the nose and ear.
• Chemical process: A process in which chemical reactions take place.
• Chest: The area of the body enclosed by the ribs, sternum, and thoracic vertebrae, containing the heart and lungs.
• Chest pain: A sensation of pain, tightness, or discomfort in the chest area, which can be a symptom of conditions ranging from benign to life-threatening, including heart attack or angina.
• Childbirth: The process of giving birth to a baby, involving labor and delivery.
• Chills: A feeling of coldness occurring during a high fever, but which does not involve an actual drop in body temperature.
• Chin: The protruding part of the face below the mouth, formed by the apex of the lower jaw.
• Choana: The posterior openings of the nasal cavity that connect to the pharynx.
• Cholecalciferol: Vitamin D3, a form of vitamin D found in animal sources and synthesized by the skin when exposed to sunlight.
• Cholesterol: A type of fat, or lipid, which is essential for the body's cellular structures but can lead to heart disease when levels are too high.
• Chondrin: A substance found in cartilage that gives it its resilience and elasticity.
• Chromosome: A thread-like structure of nucleic acids and protein found in the nucleus of most living cells, carrying genetic information in the form of genes.
• Chronic (medicine): Describing a disease or condition that is persistent or otherwise long-lasting in its effects.
• Chronic condition: A health condition or disease that is persistent or otherwise long-lasting in its effects.
• Chronic fatigue syndrome: A complex disorder characterized by extreme fatigue that cannot be explained by any underlying medical condition.
• Chronic kidney disease: A long-term condition where the kidneys do not work as well as they should.
• Cilia: Microscopic, hair-like structures that extend from the surface of nearly all mammalian cells, capable of rhythmically beating to move fluid or mucus across the cell surface.
• Ciliary body: A structure in the eye that includes the ciliary muscle, which controls the shape of the lens, and the ciliary epithelium, which produces the aqueous humor.
• Ciliary muscle: A ring of smooth muscle in the eye's middle layer (vascular layer) that controls accommodation for viewing objects at varying distances and regulates the flow of aqueous humor into Schlemm's canal.
• Circadian rhythm: Physical, mental, and behavioral changes that follow a 24-hour cycle, responding primarily to light and darkness in an organism's environment.
• Circulatory system: The system that circulates blood and lymph through the body, consisting of the heart, blood vessels, blood, lymph, and the lymphatic vessels and glands.
• Clavicle: A long bone that serves as a strut between the shoulder blade and the sternum or breastbone. Also known as the collarbone.
• Claw: A curved, pointed appendage, found at the end of a toe or finger in many mammals, birds, and some reptiles.
• Clinic: A facility or establishment where patients are given outpatient medical treatment.
• Clinical coder: A health profession involved in the classification of medical diagnoses and procedures in coded format.
• Clinical research: A branch of healthcare science that determines the safety and effectiveness of medications, devices, diagnostic products, and treatment regimens intended for human use.
• Clitoris: A female sex organ present in mammals, ostriches, and a limited number of other animals.
• Coccydynia: Pain in the coccyx or tailbone area, often brought on by sitting too abruptly.
• Cochlea: A spiral-shaped cavity forming a major part of the inner ear, responsible for transforming the sound in mechanical energy into nerve impulses.
• Coeliac disease: An autoimmune disorder that primarily affects the small intestine, occurring in people genetically predisposed to it.
• Cognition: The mental action or process of acquiring knowledge and understanding through thought, experience, and the senses.
• Cognitive development: The construction of thought processes, including remembering, problem-solving, and decision-making, from childhood through adolescence to adulthood.
• Cognitive psychology: The branch of psychology that studies mental processes including how people think, perceive, remember, and learn.
• Collagen: The main structural protein found in skin and other connective tissues, widely used in purified form for cosmetic surgical treatments.
• Colloquialism: A word or phrase that is not formal or literary, typically one used in ordinary or familiar conversation.
• Colon (anatomy): The final part of the digestive system in most vertebrates; it extracts water and salt from solid wastes before they are eliminated from the body.
• Colonoscopy: An endoscopic examination of the large bowel and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus.
• Colorectal surgery: A field in medicine dealing with disorders of the rectum, anus, and colon.
• Commissural fiber: Nerve fibers that connect the two hemispheres of the brain.
• Common bile duct: A duct in the gastrointestinal tract that conveys bile from the liver and gallbladder to the duodenum.
• Common carotid artery: A major artery that supplies blood to the head and neck.
• Common cold: A viral infectious disease of the upper respiratory tract that primarily affects the nose.
• Common hepatic duct: A duct that carries bile from the liver and gallbladder to the duodenum.
• Common iliac arteries: Two large arteries that originate from the abdominal aorta and supply blood to the pelvis, abdominal wall, and legs.
• Common iliac artery: Singular form, referring to one of the two common iliac arteries.
• Common iliac vein: A vein located in the pelvis that drains blood from the lower limbs and pelvis into the inferior vena cava.
• Communication: The act of conveying meanings from one entity or group to another through the use of mutually understood signs, symbols, and semiotic rules.
• Complex system: A system composed of many components which may interact with each other.
• Computer science: The study of algorithmic processes, computational machines, and computation itself.
• Conducting zone: Regions of the respiratory system that transport air to the sites of gas exchange, including all the structures of the airways from the nose or mouth down to the terminal bronchioles.
• Conductive hearing loss: Hearing loss that occurs when there is a problem conducting sound waves anywhere along the route through the outer ear, tympanic membrane (eardrum), or middle ear.
• Cone cell: One of the two types of photoreceptor cells in the retina of the eye, providing color vision and sharp central vision.
• Congenital: A condition that is present from birth, which can be inherited or caused by environmental factors.
• Congenital heart disease: A defect in the structure of the heart and great vessels which is present at birth.
• Conjugated bilirubin: Bilirubin that has been processed by the liver and is excreted in bile.
• Connective tissue: Tissue that supports, binds together, and protects tissues and organs of the body.
• Contact lens: A thin lens placed directly on the surface of the eye to correct visual defects.
• Coronary arteries: Arteries that supply blood to the heart muscle.
• Coronary artery disease: A disease characterized by the impairment of blood supply to the heart muscle, usually due to atherosclerosis of the coronary arteries.
• Coronary circulation: The circulation of blood in the blood vessels of the heart muscle (myocardium).
• Corpus callosum: A wide, thick nerve tract consisting of a flat bundle of commissural fibers, beneath the cortex in the eutherian brain at the longitudinal fissure, connecting the left and right cerebral hemispheres, enabling communication between them.
• Cortisol: A steroid hormone produced by the adrenal cortex, involved in the response to stress and in the metabolism of proteins, carbohydrates, and fats.
• Cosmetic surgery: Surgery performed to enhance visual appearance of the body, not necessarily for health reasons.
• Costal cartilages: Bars of hyaline cartilage that extend along the anterior ends of the ribs, contributing to the elasticity and expansion capacity of the rib cage.
• Cough: A sudden and often repetitively occurring protective reflex which helps to clear the large breathing passages from fluids, irritants, foreign particles, and microbes.
• Coughing: The act of expelling air from the lungs with a sudden sharp sound; the reflex action to clear the airways of mucus and irritants.
• Cranial nerves: Twelve pairs of nerves that emerge directly from the brain, not from the spinal cord, and pass through various foramina in the skull to innervate parts of the head and neck.
• Crocodilian: A member of the order Crocodilia, which includes crocodiles, alligators, caimans, and the gharial.
• Cubital fossa: The triangular area on the anterior view of the elbow of a human or other hominid animal.
• Cuboid bone: One of the seven tarsal bones located on the lateral side of the foot.
• Cuneiform bone: Any of the three bones in each foot located between the ankle and the first metatarsals.
• Cure: The restoration of health from a disease or condition, or the process by which this restoration occurs.
• Cutaneous branch: A branch of a nerve or blood vessel that serves the skin.
• Cystic duct: The short duct that joins the gallbladder to the common bile duct; it carries bile in and out of the gallbladder.
• Cytogenetics: The branch of genetics that studies the structure and function of the cell, especially the chromosomes.
• Cytokine: A broad and loose category of small proteins that are important in cell signaling. Their release has an effect on the behavior of cells around them.
• Cytology: The branch of biology concerned with the structure and function of plant and animal cells.

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• Death: The cessation of all biological functions that sustain a living organism.
• Decompression sickness: A condition arising from dissolved gases coming out of solution into bubbles inside the body upon depressurization.
• Deep circumflex iliac vein: A vein that accompanies the deep iliac circumflex artery and drains into the external iliac vein.
• Deep temporal arteries: Arteries that supply blood to the temporal muscle, involved in mastication.
• Deep vein: A vein that is deep in the body, as opposed to superficial veins that are close to the body's surface.
• Defecation: The final act of digestion, by which organisms eliminate solid, semisolid, or liquid waste material from the digestive tract via the anus.
• Deltoid muscle: A large, triangular muscle covering the shoulder joint and used for lifting and rotating the arm.
• Deltopectoral groove: A groove between the deltoid and the pectoral muscles of the chest, important for venous access and lymphatic drainage.
• Deltopectoral triangle: A space through which the cephalic vein passes between the deltoid and pectoral muscles.
• Delusion: A firm belief in something that is not true or based on reality, often occurring as a symptom of psychiatric disorders.
• Dementia: A broad category of brain diseases that cause a long-term and often gradual decrease in the ability to think and remember.
• Dengue virus: A mosquito-borne virus causing dengue fever, a tropical disease with symptoms such as fever, headache, muscle and joint pains, and a skin rash.
• Dentate line: The anatomical line within the anal canal that separates the upper two-thirds and the lower third, important in determining the type of cells present and the type of anal pathology.
• Dentist: A healthcare professional specializing in the diagnosis, prevention, and treatment of diseases and conditions of the oral cavity.
• Dentistry: The branch of medicine concerned with the study, diagnosis, prevention, and treatment of diseases, disorders, and conditions of the oral cavity.
• Dentition: The development of teeth and their arrangement in the mouth.
• Depression (mood): A mental disorder characterized by a pervasive and persistent low mood that is accompanied by low self-esteem and by a loss of interest or pleasure in normally enjoyable activities.
• Dermal bone: A type of bone that forms in the skin and does not arise from cartilage, typically found in the skulls of vertebrates.
• Dermatitis: Inflammation of the skin, characterized by itchy, erythematous, vesicular, weeping, and crusting patches.
• Detoxification: The physiological or medicinal removal of toxic substances from a living organism, including the human body.
• Developmental biology: The study of the process by which animals and plants grow and develop, and is synonymous with ontogeny.
• Developmental disorder: A group of psychiatric conditions originating in childhood that involve serious impairment in different areas.
• Developmental milestones: Age-specific tasks that most children can do at a certain age range, used to gauge physical, social, linguistic, and cognitive development.
• Diabetes mellitus: A group of metabolic disorders characterized by a high blood sugar level over a prolonged period of time.
• Diabetes mellitus type 1: A form of diabetes mellitus that results from the autoimmune destruction of insulin-producing beta cells in the pancreas.
• Diabetes mellitus type 2: A long-term metabolic disorder that is characterized by high blood sugar, insulin resistance, and relative lack of insulin.
• Diabetic foot ulcer: An open sore or wound that occurs in approximately 15 percent of patients with diabetes and is commonly located on the bottom of the foot.
• Diabetic ketoacidosis: A serious complication of diabetes that occurs when your body produces high levels of blood acids called ketones.
• Diabetic retinopathy: A diabetes complication that affects eyes and has the potential to cause blindness.
• Diagnosis: The identification of the nature and cause of a certain phenomenon, often achieved through diagnostic procedures and tests.
• Diagnostics: The field of medicine concerned with the determination of the nature of diseases and conditions by examination and testing.
• Diarrhea: The condition of having at least three loose, liquid, or watery bowel movements each day.
• Diastole: The phase of the heartbeat when the heart muscle relaxes and allows the chambers to fill with blood.
• Dietary reference intake: A system of nutrition recommendations from the Institute of Medicine of the U.S. National Academy of Sciences.
• Differential diagnosis: The distinguishing of a particular disease or condition from others that present similar clinical features.
• Digestion: The process by which food is broken down into smaller components that can be absorbed into the bloodstream.
• Digestive enzyme: Enzymes that break down polymeric macromolecules into their smaller building blocks, in order to facilitate their absorption by the body.
• Digestive system: The series of organs and glands in the body that process food.
• Dimpling: A small, natural indentation in the flesh on a part of the human body, notably in the cheek or on the chin.
• Disabilities: Conditions that result in impairments in physical, mental, or sensory functions that affect participation in normal activities.
• Disability: An impairment that may be cognitive, developmental, intellectual, mental, physical, sensory, or some combination of these, and results in restrictions on an individual's ability to participate in what is considered normal in their everyday society.
• Disease: A particular abnormal condition that negatively affects the structure or function of part or all of an organism, and that is not due to any external injury.
• Diseases: Plural form of disease, referring to multiple abnormal conditions affecting organisms.
• Distal phalange: The bone at the tip of the fingers or toes; the most distal bone of the digits.
• Dorsal root ganglion: A cluster of nerve cell bodies (a ganglion) in a dorsal root of a spinal nerve.
• Duct (anatomy): A circumscribed channel leading from one structure to another, especially one for conveying fluid.
• Duodenum: The first section of the small intestine immediately beyond the stomach, leading to the jejunum.
• Dysbarism: The medical condition resulting from the pressure differences between the inside of the body and the external environment and is seen in activities such as diving, aviation, and space travel.
• Dyspareunia: Difficult or painful sexual intercourse.
• Dysuria: Painful or difficult urination, often a symptom of a urinary tract infection.

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• Ear: The organ of hearing and balance in humans and other vertebrates, especially the external part of this.
• Ear canal: A tube running from the outer ear to the middle ear, also known as the external auditory canal.
• Eating disorder: Mental disorders defined by abnormal eating habits that negatively affect a person's physical or mental health.
• Ecology: The branch of biology that deals with the relations of organisms to one another and to their physical surroundings.
• Efferent nerve fiber: Nerve fibers that carry signals away from the central nervous system to effectors such as muscles and glands.
• Efficacy: The ability to produce a desired or intended result, often used in a medical context to refer to the effectiveness of a treatment.
• Egg cell: The female reproductive cell or gamete in oogamous organisms, also known as an ovum.
• Ejaculation: The discharge of semen from the male reproductive tract as a result of orgasm.
• Ejaculatory duct: A duct through which semen is ejaculated, running from the vas deferens to the urethra.
• Elastic tissue: A type of connective tissue that allows many tissues in the body to resume their shape after stretching or contracting.
• Elbow: The joint connecting the forearm to the upper arm, allowing for the bending and straightening of the arm.
• Elbow-joint: Another term for the elbow, emphasizing its function as a joint.
• Elbow joint: The hinge joint between the distal end of the humerus in the upper arm and the proximal ends of the ulna and radius in the forearm.
• Electrochemical: Relating to processes that involve both electrical and chemical changes.
• Electrolyte: Minerals in blood and other body fluids that carry an electric charge, important for hydration, blood pH, and muscle function.
• Electrolytes: Plural form of electrolyte, referring to multiple substances that become ions in solution and acquire the capacity to conduct electricity.
• Electromyography (EMG): A diagnostic procedure to assess the health of muscles and the nerve cells that control them.
• Embryo: An early stage of development of a multicellular organism following fertilization and before fetal stages in species that undergo such processes.
• Embryology: The branch of biology and medicine concerned with the study of embryos and their development.
• Emergency medicine: The medical specialty concerned with the care of illnesses or injuries requiring immediate medical attention.
• Emotion: A complex state of feeling that results in physical and psychological changes that influence thought and behavior.
• Endocarditis: Inflammation of the inner layer of the heart, the endocardium, usually involving the heart valves.
• Endocardium: The innermost layer of tissue that lines the chambers of the heart.
• Endocrine: Relating to or denoting glands that secrete hormones or other products directly into the blood.
• Endocrine gland: Glands of the endocrine system that release hormones directly into the bloodstream.
• Endocrine system: The collection of glands that produce hormones that regulate metabolism, growth and development, tissue function, sexual function, reproduction, sleep, and mood, among other things.
• Endocrinology: The branch of physiology and medicine concerned with endocrine glands and hormones.
• Endothelial cell: Cells that line the blood vessels, lymph vessels, and the heart, playing a key role in controlling the passage of materials and the transit of white blood cells into and out of the bloodstream.
• Enterocytes: The absorptive epithelial cells that line the inner surface of the small and large intestines.
• Environment (biophysical): The biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution.
• Enzymes: Biological molecules (proteins) that act as catalysts and help complex reactions occur everywhere in life.
• Epicardium: The outer layer of the heart wall, consisting of an inner visceral layer of the pericardium that lies on the heart muscle.
• Epidemiology: The study and analysis of the distribution (who, when, and where), patterns, and determinants of health and disease conditions in defined populations.
• Epidermis: The outermost layer of skin, providing a waterproof barrier and creating our skin tone.
• Epididymis: A tube at the back of the testicle that stores and carries sperm.
• Epiglottis: A leaf-shaped flap of cartilage located behind the tongue, at the top of the larynx, which prevents food and drink from entering the windpipe during swallowing.
• Epilepsy: A group of neurological disorders characterized by epileptic seizures.
• Epileptic seizure: A brief episode of signs or symptoms due to abnormally excessive or synchronous neuronal activity in the brain.
• Epithelium: One of the four basic types of animal tissue, along with connective tissue, muscle tissue, and nervous tissue. It lines both the outside (skin) and the inside cavities and lumen of bodies.
• Equilibrioception: The sense of balance or equilibrium.
• Erection: The stiffening and rising of the penis, which occurs during sexual arousal, though it can also happen in non-sexual situations.
• Erector spinae muscles: A group of muscles that run more or less vertically along the spine from the sacrum to the base of the skull.
• Ergocalciferol: Also known as vitamin D2, a type of vitamin D found in plants and dietary supplements.
• Ernst Heinrich Weber: A German physician who is considered one of the founders of experimental psychology.
• Erogenous zone: An area of the human body that has heightened sensitivity, the stimulation of which may generate a sexual response.
• Erythema: Redness of the skin or mucous membranes, caused by hyperemia (increased blood flow) in superficial capillaries.
• Esophagus: The tube that connects the throat (pharynx) with the stomach; the gullet.
• Estrogen: The primary female sex hormone responsible for the development and regulation of the female reproductive system and secondary sex characteristics.
• Euphoria: A feeling or state of intense excitement and happiness.
• Evidence-based practice: A conscientious, problem-solving approach to clinical practice that incorporates the best evidence from well-designed studies, patient values and preferences, and a clinician's expertise in making decisions about a patient's care.
• Evolution: The change in the heritable characteristics of biological populations over successive generations.
• Excretion: The process by which metabolic waste is eliminated from an organism.
• Exocrine: Relating to or denoting glands that secrete their products through ducts opening onto an epithelium rather than directly into the bloodstream.
• Experiment: A procedure carried out to support, refute, or validate a hypothesis, often involving precise and controlled observation or manipulation of variables.
• Extension (kinesiology): A movement that increases the angle between the bones of the limb at a joint.
• External carotid artery: One of the two main divisions of the carotid artery, which supplies blood to the face and neck.
• External iliac artery: A large artery in the pelvic region that carries blood to the lower limb.
• External iliac vein: A vein located in the pelvic region that drains blood from the lower limb back to the heart.
• External jugular vein: A vein that drains blood from the face, neck, and scalp and empties into the subclavian vein.
• External oblique: A muscle in the abdomen that helps rotate the trunk and flex the spine.
• External os: The opening of the cervical canal of the uterus into the vagina.
• Extracellular fluid: Body fluid outside the cells, which includes interstitial fluid, blood plasma, and other body fluids.
• Extracellular matrix: A collection of extracellular molecules secreted by cells that provides structural and biochemical support to the surrounding cells.
• Extrastriate cortex: The region of the cortex located just outside the primary visual cortex that is involved in processing visual information.
• Eye: The organ of vision in humans and animals.
• Eye surgery: Surgery performed on the eye or its adnexa, typically by an ophthalmologist.
• Eyes: Plural of eye, referring to both organs of vision in an organism.

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• Face: The front part of a person's head, extending from the forehead to the chin and including the mouth, nose, eyes, and cheeks.
• Facial trauma: Physical trauma to the face, which may involve soft tissue injuries such as burns, lacerations, and bruises, or fractures of the facial bones.
• Failure to thrive: A term used in pediatric and adult medicine to describe a condition where an individual has insufficient weight gain or growth.
• Fallopian tube: One of a pair of tubes along which eggs travel from the ovaries to the uterus in the female reproductive system.
• Fallopian tubes: The plural form, referring to both tubes in the female reproductive system.
• Family (biology): A taxonomic rank in the classification of organisms that groups together related genera.
• Fascia: A band or sheet of connective tissue, primarily collagen, beneath the skin that attaches, stabilizes, encloses, and separates muscles and other internal organs.
• Fat: A natural oily substance occurring in animal bodies, especially when deposited as a layer under the skin or around certain organs.
• Fatigue: A feeling of tiredness or exhaustion or a need to rest because of lack of energy or strength.
• Fatigue (medical): Medical fatigue, a symptom of many conditions, characterized by a persistent sense of tiredness or exhaustion that does not improve with rest.
• Feces: Waste matter discharged from the bowels after food has been digested; excrement.
• Fellowship (medicine): A period of medical training in the United States and Canada that a physician or dentist may undertake after completing a specialty training program (residency).
• Female: Of or denoting the sex that can bear offspring or produce eggs, distinguished biologically by the production of gametes (ova).
• Female genital tract: The system of organs within the female reproductive system that includes structures such as the ovaries, fallopian tubes, uterus, and vagina.
• Female mammal: A mammal of the sex that produces ova or bears young.
• Female reproductive system: The organ system in females that produces eggs for reproduction and provides a place for the growth of a fetus.
• Femoral arteries: The major arteries supplying blood to the lower limbs, starting from the iliac arteries and extending down to the legs.
• Femoral artery: A large artery in the thigh that supplies blood to the lower limb.
• Femoral nerve: A major nerve in the thigh that supplies skin on the upper thigh and inner leg, and the muscles that extend the knee.
• Femoral sheath: A funnel-shaped sheath that encloses the femoral artery, vein, and canal through which lymphatics pass.
• Femoral triangle: An anatomical region of the upper inner thigh bounded by the sartorius muscle, adductor longus muscle, and the inguinal ligament, containing the femoral nerve, artery, and vein.
• Femoral vein: A blood vessel that accompanies the femoral artery in the same sheath and drains the leg of blood to be returned to the heart.
• Femur: The thigh bone, the longest and strongest bone in the human body, supporting the weight of the upper body.
• Femur head: The proximal (closest to the body) part of the femur that articulates with the pelvis at the hip joint.
• Fertilization: The fusion of gametes to initiate the development of a new individual organism or offspring.
• Fetus: A prenatal human between the embryonic state and birth.
• Fever: An increase in body temperature above the normal range, often due to an infection or illness.
• Fibrillation: An irregular, often rapid heart rate that commonly causes poor blood flow.
• Fibrocartilage: A type of cartilage that contains fibrous bundles of collagen, such as that of the intervertebral discs in the spinal cord.
• Fibromyalgia: A disorder characterized by widespread musculoskeletal pain accompanied by fatigue, sleep, memory, and mood issues.
• Fibrous joint: A type of joint connected by fibrous tissue, capable of little or no movement, such as the sutures of the skull.
• Fibula: The calf bone, a slender bone located on the lateral side of the tibia in the lower leg.
• Fine motor skill: The coordination of small muscles, in movements—usually involving the synchronization of hands and fingers—with the eyes.
• Finger: Any of the five digits extending from the palm of the hand, used for grasping or manipulating objects.
• First aid: The immediate assistance given to any person suffering from either a minor or serious illness or injury, with care provided to preserve life, prevent the condition from worsening, or to promote recovery.
• Fisheries: A commercial enterprise or an area involved in the raising or harvesting fish which is determined by some authority to be a fishery.
• Flat bone: Bones whose principal function is either extensive protection or the provision of broad surfaces for muscular attachment.
• Flaviviridae: A family of viruses that include the dengue virus, yellow fever virus, West Nile virus, and others, transmitted by ticks and mosquitoes.
• Flexion: A bending movement around a joint in a limb (as the knee or elbow) that decreases the angle between the bones of the limb at the joint.
• Food: Any nutritious substance that people or animals eat or drink or that plants absorb in order to maintain life and growth.
• Food addiction: A behavioral addiction that is characterized by the compulsive consumption of palatable (e.g., high fat and high sugar) foods.
• Food allergy: An adverse health effect arising from a specific immune response that occurs reproducibly on exposure to a given food.
• Food intolerances: Adverse reactions to foods that do not involve the individual's immune system, unlike food allergies.
• Food poisoning: Illness caused by consuming contaminated food, often with bacteria, viruses, or parasites.
• Foot: The lower extremity of the leg below the ankle, on which a person stands or walks.
• Foramen magnum: The large opening at the base of the skull through which the spinal cord passes to connect to the brain.
• Forearm: The part of a person's arm extending from the elbow to the wrist or the fingertips.
• Forehead: The part of the face above the eyebrows.
• Forelimb: The front limb or appendage of an animal.
• Fossa (anatomy): A depression or hollow, usually in a bone.
• Frequent urination: Needing to urinate more often than usual, often without a significant increase in the total volume of urine.
• Frontal bone: A bone in the human skull that forms the forehead, the roofs of the orbits (eye sockets), and most of the anterior part of the cranial floor.
• Frontal lobe: The part of the brain located at the front of each cerebral hemisphere, involved in motor function, problem solving, spontaneity, memory, language, initiation, judgment, impulse control, and social and sexual behavior.
• Frontal nerve: The largest branch of the ophthalmic division of the trigeminal nerve, supplying the skin of the forehead and scalp.
• Frontal sinus: One of the four pairs of paranasal sinuses that are situated behind the brow ridges.
• Frontalis muscle: A muscle which covers parts of the skull, used to raise the eyebrows and wrinkle the forehead.
• Function (biology): The special, normal, or proper activity of an organ or part.
• Functional imaging: Medical imaging techniques used to observe metabolic processes and other physiological activities in the body, especially in the brain.

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• Gall bladder or Gallbladder: A small organ beneath the liver that stores bile secreted by the liver and releases it into the small intestine.
• Gamete: A mature haploid male or female germ cell that is able to unite with another of the opposite sex in sexual reproduction to form a zygote.
• Gametes: The plural form of gamete, referring to both sperm and egg cells.
• Ganglion: A structure containing a number of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber.
• Gas exchange: The biological process through which different gases are transferred in opposite directions across a specialized respiratory surface.
• Gastrocnemius muscle: A major muscle in the back part of the lower leg or calf, involved in walking, running, and jumping.
• Gastroenterology: The branch of medicine focused on the digestive system and its disorders.
• Gastrointestinal system: The system of organs responsible for digestion, including the mouth, esophagus, stomach, pancreas, liver, gallbladder, small intestine, large intestine, and anus.
• Gastrointestinal tract: The part of the gastrointestinal system through which food passes, from the mouth to the anus, including the stomach and intestines.
• Gastroscopy: A medical procedure where a thin, flexible tube with a light and camera (gastroscope) is inserted into the stomach through the mouth to examine the gastrointestinal tract.
• Gene: A unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring.
• Gene therapy: A medical field which focuses on the treatment of diseases by altering the genes in a patient's cells.
• General surgery: A surgical specialty that focuses on abdominal contents including the esophagus, stomach, small bowel, colon, liver, pancreas, gallbladder, appendix, and bile ducts, among other organs.
• Genetics: The study of genes, genetic variation, and heredity in living organisms.
• Genitourinary system: The organ system of the reproductive organs and the urinary system.
• Genome: An organism's complete set of DNA, including all of its genes.
• Genus: A rank in the biological classification system (taxonomy) that is used in the biological naming of living things.
• Geriatrics: The branch of medicine or social science dealing with the health and care of old people.
• Gerontology: The study of the social, cultural, psychological, cognitive, and biological aspects of aging.
• Gestation: The process or period of developing inside the womb between conception and birth.
• Gland: An organ in the human or animal body that secretes particular chemical substances for use in the body or for discharge into the surroundings.
• Glasses: Frames bearing lenses worn in front of the eyes, normally for vision correction or eye protection.
• Glaucoma: A group of eye conditions that can cause blindness by damaging the optic nerve, usually due to excessively high intraocular pressure.
• Glenohumeral joint: The shoulder joint, a ball and socket joint between the scapula and the humerus.
• Glossary of medicine: A list of definitions for terms and concepts used in medicine and healthcare fields.
• Glucagon: A hormone formed in the pancreas that promotes the breakdown of glycogen to glucose in the liver.
• Gluteus maximus muscle: The largest and most superficial of the three gluteal muscles that make up the buttocks, responsible for movement of the hip and thigh.
• Gluteus medius muscle: A muscle of the upper buttock that acts on the hip to abduct the thigh and stabilize the pelvis during walking.
• Glycogen: A multibranched polysaccharide of glucose that serves as a form of energy storage in animals and fungi.
• Gomphosis: A joint that binds the teeth to bony teeth sockets in the maxillary bone and mandible.
• Gonad: An organ that produces gametes; a testis or ovary.
• Gout: A form of inflammatory arthritis characterized by recurrent attacks of a red, tender, hot, and swollen joint, caused by elevated levels of uric acid in the blood.
• Gracilis muscle: A slender muscle of the inner thigh, involved in the adduction of the leg and flexion of the knee.
• Great saphenous vein: The longest vein in the body, running along the length of the lower limb, and used in coronary artery bypass surgery and in diagnosing venous disease.
• Great vessels: The major arteries and veins that carry blood to and from the heart.
• Greek language: An independent branch of the Indo-European family of languages native to Greece and other parts of the Eastern Mediterranean.
• Green: A color that is associated with nature, life, and health.
• Growth hormone: A hormone that stimulates growth, cell reproduction, and cell regeneration in humans and other animals.
• Gustatory cortex: The brain region involved in the perception of taste.
• Gynaecology or Gynecology: The medical practice dealing with the health of the female reproductive systems (vagina, uterus, and ovaries) and the breasts.

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• Hair follicle: A dynamic organ found in mammalian skin, responsible for hair production.
• Hallucination: A perception in the absence of external stimulus that has qualities of real perception.
• Hand: The end part of a person's arm beyond the wrist, including the palm, fingers, and thumb.
• Hand surgery: A field of medicine that deals with problems of the hand, wrist, and forearm that may require surgery.
• Haploid: A cell or nucleus having a single set of unpaired chromosomes, especially a germ cell.
• Hard palate: The bony front part of the palate forming the roof of the human mouth.
• Hay fever: An allergic reaction characterized by sneezing, runny or blocked nose, and itchy eyes, due to pollen from grasses and plants.
• Hazard: A potential source of harm or adverse health effect on a person or persons.
• Head: The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
• Head and neck: An anatomical region that includes the structures of the head and neck, often focused on in medical studies and treatments.
• Headache: A pain or discomfort in the head, scalp, or neck, often associated with tension, migraine, or sinus issues.
• Health: A state of complete physical, mental, and social well-being and not merely the absence of disease or infirmity.
• Health care: The maintenance or improvement of health via the prevention, diagnosis, treatment, recovery, or cure of disease, illness, injury, and other physical and mental impairments in people.
• Health problems: Issues that can affect one's health, ranging from minor to severe, including diseases, disorders, and injuries.
• Health profession: Occupations that focus on providing health care for individuals.
• Health professional: An individual who provides preventive, curative, promotional, or rehabilitative health care services in a systematic way to individuals, families, or communities.
• Healthcare provider: An individual or institution that provides medical services to individuals or communities.
• Healthcare science: A group of sciences and technologies applied to health and well-being, encompassing a wide range of disciplines.
• Hearing: The ability to perceive sounds by detecting vibrations through an organ such as the ear.
• Heart: A muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system.
• Heart arrhythmia: Any of a number of conditions in which the electrical activity of the heart is irregular or is faster or slower than normal.
• Heart chamber: A space within the heart, there are four chambers in the human heart: two atria and two ventricles.
• Heart disease: A range of conditions that affect the heart, such as coronary artery disease, heart rhythm problems (arrhythmias), and heart defects.
• Heart failure: A condition in which the heart is unable to pump sufficiently to maintain blood flow to meet the body's needs.
• Heart rate: The speed of the heartbeat measured by the number of contractions (beats) of the heart per minute (bpm).
• Heart sounds: The noises generated by the beating heart and the resultant flow of blood through it, typically heard with a stethoscope.
• Heart transplantation: A surgical transplant procedure performed on patients with end-stage heart failure or severe coronary artery disease.
• Heel: The prominence at the posterior end of the foot, based on the projection of the calcaneus bone.
• Hematemesis: The vomiting of blood.
• Hematology: The branch of medicine concerned with the study, diagnosis, treatment, and prevention of diseases related to blood.
• Hematoma: A solid swelling of clotted blood within the tissues.
• Hematopoiesis: The formation of blood cellular components.
• Hematopoietic stem cell: Stem cells that give rise to other blood cells, located in the bone marrow.
• Hematuria: The presence of blood in urine.
• Hemodialysis: A process of purifying the blood of a person whose kidneys are not working normally.
• Hemoperfusion: A treatment technique in which large volumes of the patient's blood are passed over an adsorbent substance in order to remove toxic substances from the blood.
• Hemophilia: A rare disorder in which your blood doesn't clot normally because it lacks sufficient blood-clotting proteins (clotting factors).
• Hemoptysis: Coughing up blood or blood-stained mucus from the bronchi, larynx, trachea, or lungs.
• Hemorrhoid: Swollen and inflamed veins in the rectum and anus that cause discomfort and bleeding.
• Hepatic duct: The duct that conveys bile from the liver into the bile duct.
• Hepatocyte: The main cell type of the liver, performing multiple functions.
• Herbivores: Animals that eat plants exclusively.
• Heredity: The passing on of physical or mental characteristics genetically from one generation to another.
• Hermaphroditic: Having both male and female reproductive organs.
• Hernia: A condition in which part of an organ is displaced and protrudes through the wall of the cavity containing it.
• Hindbrain: The posterior part of the brain, comprising the cerebellum, pons, and medulla oblongata.
• Hinge joint: A type of synovial joint that allows movement in one plane, such as the elbow and knee.
• Hip: The region on each side of the pelvis, where the femur (thigh bone) joins the pelvis.
• Hip bone: A large bone that forms the basis of the human pelvis, consisting of three parts: ilium, ischium, and pubis.
• Hip joint: A ball-and-socket joint between the hip bone and the femur.
• Hippocampus: A major component of the brains of humans and other vertebrates, involved in the consolidation of information from short-term memory to long-term memory, and in spatial memory that enables navigation.
• Histology: The study of the microscopic anatomy of cells and tissues of plants and animals.
• Homeostasis: The ability of a system, especially the physiological system of higher animals, to maintain internal stability, owing to the coordinated response of its parts to any situation or stimulus that would tend to disturb its normal condition or function.
• Hormone: Chemical substances produced in the body that regulate the activity of cells or organs.
• Hospice: A type of care and a philosophy of care that focuses on the palliation of a chronically ill, terminally ill, or seriously ill patient's pain and symptoms.
• Hospital: A health care institution providing patient treatment with specialized medical and nursing staff and medical equipment.
• Hospital medicine: A medical specialty dedicated to the delivery of comprehensive medical care to hospitalized patients.
• Host (biology): An organism that harbors a parasite, or a mutual or commensal symbiont, typically providing nourishment and shelter.
• Human: A bipedal primate species belonging to the genus Homo, especially Homo sapiens.
• Human abdomen: The part of the body between the thorax (chest) and pelvis, in humans, housing the digestive organs.
• Human anatomy: The scientific study of the morphology of the adult human.
• Human back: The large posterior area of the human body, rising from the top of the buttocks to the back of the neck and the shoulders.
• Human body: The entire structure of a human being comprising a head, neck, trunk (which includes the thorax and abdomen), arms and hands, legs and feet.
• Human brain: The central organ of the human nervous system, located in the head and protected by the skull, functioning as the coordinating center of sensation and intellectual and nervous activity.
• Human digestive system: The system used in the human body for the process of digestion, which includes the gastrointestinal tract plus the accessory organs of digestion.
• Human embryogenesis: The process by which the embryo is formed and develops.
• Human eye: The organ of vision in humans, allowing the perception of light and visual detail.
• Human foot: The lower extremity of the leg below the ankle, on which a person stands or walks.
• Human head: The upper part of the human body, or the front or upper part of the body of an animal, typically separated from the rest of the body by a neck, and containing the brain, mouth, and sense organs.
• Human heart: A muscular organ in humans which pumps blood through the blood vessels of the circulatory system.
• Human leg: The entire lower limb of the human body, including the foot, thigh, and even the hip or gluteal region.
• Human mandible: The lower jaw or jawbone, the largest, strongest, and lowest bone in the human face.
• Human mouth: The opening in the human face which functions as the beginning of the digestive system and in the intake of food and air.
• Human nose: The protruding part of the face that bears the nostrils and functions as the organ of smell and as part of the respiratory system.
• Human penis: The male reproductive organ in humans, part of the urinary and reproductive systems.
• Human pharynx: The part of the throat situated immediately posterior to the mouth and nasal cavity, and cranial to the esophagus and larynx.
• Human reproductive system: The organ system involved in the reproduction process, including the genital organs.
• Human skeleton: The internal framework of the body, composed of 206 bones in the adult, providing support, protection, and movement.
• Human skin: The outer covering of the body, the largest organ of the integumentary system.
• Human skull: The bony structure that forms the head in the human skeleton, supports the structures of the face, and protects the brain.
• Human tooth: One of the hard, white structures in the mouth used for biting and chewing.
• Human vertebral column: The spine or backbone, consisting of 24 articulating vertebrae, and nine fused vertebrae in the sacrum and the coccyx.
• Human vestigiality: Refers to those structures in humans that have lost all or most of their original function through evolution.
• Humans: Plural form of human, referring to the species Homo sapiens collectively.
• Humerus: The bone of the upper arm or forelimb, forming joints at the shoulder and the elbow.
• Humoral immunity: A part of the immune system that is mediated by macromolecules found in extracellular fluids such as secreted antibodies, complement proteins, and certain antimicrobial peptides.
• Hyaline: A type of smooth, translucent cartilage that is found in joints, respiratory tract, and the embryonic skeleton.
• Hydrocele: A type of swelling in the scrotum that occurs when fluid collects in the thin sheath surrounding a testicle.
• Hymen: A thin membrane that partially covers the external vaginal opening in females.
• Hyperbilirubinemia: A condition in which there is too much bilirubin in the blood, a substance that results from the breakdown of red blood cells, leading to jaundice.
• Hyperglycemia: A condition characterized by an excessive amount of glucose in the bloodstream, often associated with diabetes mellitus.
• Hyperhidrosis: A condition characterized by abnormally increased sweating, in excess of that required for regulation of body temperature.

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• Ilium (bone): The uppermost and largest bone of the pelvis, contributing to the greater pelvis and providing support for the body's weight in sitting and standing positions.
• Illness: A state in which a person's physical, emotional, or mental condition is impaired or in a state of distress, often due to disease or injury.
• Immune deficiency: A state in which the immune system's ability to fight infectious disease and cancer is compromised or entirely absent.
• Immune system: The host defense system comprising many biological structures and processes within an organism that protects against disease.
• Immunohistochemistry: A laboratory method that uses antibodies to detect antigens (specific proteins) in cells of a tissue section.
• Immunology: The branch of medicine and biology concerned with immunity, the study of the immune system in all organisms.
• Impulsivity: A tendency to act on a whim, displaying behavior characterized by little or no forethought, reflection, or consideration of the consequences.
• In situ: A term used to describe a condition or process that takes place in its original location.
• In vitro: Studies or processes performed or taking place in a test tube, culture dish, or elsewhere outside a living organism.
• In vivo: Studies or processes performed or taking place in a living organism.
• Incus: A small anvil-shaped bone in the middle ear, transmitting vibrations between the malleus and stapes.
• Index finger: The second digit of the human hand, located between the thumb and the middle finger.
• Infant: A very young child or baby, typically from birth until the age of one year.
• Infantile Refsum disease: A rare inherited disorder characterized by the accumulation of phytanic acid in the plasma and tissues, leading to developmental delays and other health issues.
• Infection: The invasion and multiplication of microorganisms such as bacteria, viruses, and parasites that are not normally present within the body.
• Infectious disease: Diseases caused by pathogenic microorganisms, such as bacteria, viruses, parasites or fungi; the diseases can be spread, directly or indirectly, from one person to another.
• Inferior oblique muscle: A muscle in the orbit that controls the upward and outward movement of the eye.
• Inferior ophthalmic vein: A vein in the orbit that drains blood from the eye and surrounding structures.
• Inferior thyroid artery: An artery that supplies blood to the thyroid gland and surrounding areas of the neck.
• Inferior tibiofibular joint: A joint between the lower parts of the tibia and fibula of the leg.
• Inferior vena cava: A large vein that carries deoxygenated blood from the lower body to the heart.
• Infirmity: Physical or mental weakness, often due to illness or age.
• Inflammation: A biological response to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators.
• Inflammatory arthritis: A group of diseases characterized by inflammation of the joints and surrounding tissues, including rheumatoid arthritis and psoriatic arthritis.
• Influenza: An infectious viral disease that affects the respiratory system, characterized by fever, chills, muscle pain, and respiratory symptoms.
• Infratemporal fossa: An anatomical space located below the temporal fossa and deep to the ramus of the mandible, containing several muscles, the lower part of the temporalis muscle, and various vessels and nerves.
• Inguinal canal: A passage in the lower anterior abdominal wall which in men conveys the spermatic cord and in women the round ligament.
• Inguinal ligament: A band running from the pubic tubercle to the anterior superior iliac spine, forming the lower border of the abdomen.
• Injury: Damage to the body caused by external force, which may be physical or psychological.
• Inner ear: The innermost part of the vertebrate ear, responsible for sound detection and balance, consisting of the cochlea, vestibule, and semicircular canals.
• Inspection (medicine): The visual examination of the body, including its movements and posture, for the purpose of medical diagnosis.
• Institute of Medicine: An American non-profit, non-governmental organization founded in 1970, now known as the National Academy of Medicine, which provides expert advice on issues relating to biomedical science, medicine, and health.
• Insulin: A hormone produced in the pancreas that regulates the amount of glucose in the blood.
• Integumentary system: The organ system that protects the body from various kinds of damage, such as loss of water or abrasion from the outside, and includes the skin and its appendages (including hair, scales, feathers, and nails).
• Intensive care medicine: A branch of medicine concerned with the diagnosis and management of life-threatening conditions requiring sophisticated organ support and invasive monitoring.
• Intercalated disc: Specialized connections between myocardial cells containing gap junctions and desmosomes that facilitate the synchronized contraction of the heart muscle.
• Interdisciplinary: Involving two or more academic, scientific, or artistic disciplines.
• Intermediate phalanges: The bones in the fingers or toes located between the proximal and distal phalanges.
• Internal Medicine: A medical specialty dealing with the prevention, diagnosis, and treatment of adult diseases.
• Internal carotid artery: A major artery that supplies blood to the brain.
• Internal iliac arteries: Arteries that supply blood to the pelvis, gluteal region, and the medial compartment of the thigh.
• Internal iliac vein: A vein that drains blood from the pelvis.
• Internal jugular vein: A vein that collects blood from the brain and the superficial parts of the face and neck.
• Internal medicine: The medical specialty dealing with the prevention, diagnosis, and treatment of internal diseases in adults.
• Internship (medicine): A period of medical training that a doctor may undertake after completing a medical degree.
• Interstitial fluid: Fluid that surrounds the cells of multicellular animals, providing a means of delivering materials to the cells, intercellular communication, and waste removal.
• Interventional cardiology: A branch of cardiology that deals specifically with the catheter-based treatment of structural heart diseases.
• Interventional radiologist: A doctor specializing in the performance of minimally invasive treatments using radiologic imaging for targeting therapy.
• Intervertebral disc: A fibrocartilaginous joint between most of the vertebrae in the spine, providing shock absorption and allowing slight movement of the vertebrae.
• Intestine: The segment of the digestive system extending from the stomach to the anus, divided into the small intestine and large intestine, responsible for nutrient absorption and waste processing.
• Intestines: Plural form of intestine, referring to both the small and large parts of the digestive tract.
• Intimacy: Close familiarity or friendship; closeness.
• Intraocular lens: An implanted lens in the eye, used as a treatment for conditions such as cataracts and myopia.
• Irregular bone: Bones with a shape that does not conform to the long, short, or flat bone categories, such as the vertebrae and many skull bones.
• Ischemic heart disease: A condition characterized by reduced blood supply to the heart muscle, usually due to coronary artery disease.
• Ischioanal fossa: A fat-filled space located on either side of the anal canal and below the pelvic diaphragm.
• Ischium: The lower and back part of the hip bone.
• Itch: An irritation in the skin that elicits an urge to scratch.
• Itchiness: The sensation that leads to the desire or reflex to scratch.

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• Jaundice: A yellow discoloration of the skin, mucous membranes, and the whites of the eyes caused by increased levels of bilirubin in the blood, often indicating a problem with liver function.
• Jaw: The lower part of the face that moves when you open your mouth, including both the upper and lower parts that hold the teeth.
• Jawbone: Either of the two bones in which the teeth are set; the lower jawbone is called the mandible, and the upper jawbone is called the maxilla.
• Jejunum: The second part of the small intestine in humans and most higher vertebrates, between the duodenum and ileum, where most of the nutrients from food are absorbed.
• Joint: A structure in the human or animal body at which two parts of the skeleton are fitted together, allowing for movement or flexibility.
• Joint effusion: The presence of increased fluid in or around a joint, usually due to inflammation, injury, or infection.
• Joint pain: Discomfort, aches, and soreness in any of the body's joints, often a symptom of arthritis or another joint disorder.
• Joints: Plural form of joint, referring to the multiple areas where two or more bones meet, providing mobility and flexibility to the skeleton.
• Jugular vein: Any of several large veins in the neck, carrying blood from the head back to the heart. There are internal and external jugular veins.

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• KDa: KiloDalton, a unit of molecular weight equal to one thousand daltons, commonly used to express the size of proteins and large molecules.
• Keratinocytes: The predominant cell type in the epidermis, the outermost layer of the skin, responsible for the production of keratin.
• Kernicterus: A rare but serious form of brain damage that can occur in newborns with jaundice, caused by excessive bilirubin.
• Kidney: One of a pair of organs in the abdominal cavity of mammals, birds, and reptiles, which excrete urine.
• Kidney dialysis: A procedure to remove waste products and excess fluid from the blood when the kidneys stop working properly.
• Kidney disease: Any disease or disorder that affects the function of the kidneys.
• Kidney failure: A condition in which the kidneys lose the ability to remove waste and balance fluids.
• Kidney stone: A solid piece of material that forms in a kidney when substances that are normally found in the urine become highly concentrated.
• Kidney transplantation: A surgical procedure to place a healthy kidney from a live or deceased donor into a person whose kidneys no longer function properly.
• Kidneys: Plural of kidney, referring to both organs.
• Kiss: The act of pressing one's lips against the lips or other body parts of another person or an object.
• Knee: The joint between the thigh and the lower leg in humans.
• Knee joint: The largest and most complex joint in the human body, connecting the femur (thigh bone) to the tibia (shin bone).
• Kneecap: Also known as the patella, a small flat triangular bone in front of the knee joint.
• Korsakoff syndrome: A chronic memory disorder caused by severe deficiency of thiamine (vitamin B1), most commonly caused by alcohol misuse.

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• LOINC: Logical Observation Identifiers Names and Codes, a database and universal standard for identifying medical laboratory observations.
• Labia: Parts of the female genitalia; the labia majora and labia minora protect the openings of the vagina and the urethra.
• Labyrinthitis: An inner ear disorder that causes a structure deep inside your ear (the labyrinth) to become inflamed, affecting hearing and balance.
• Lacrimal artery: An artery that supplies blood to the lacrimal gland and other structures in the orbit.
• Lacrimal nerve: A nerve that provides sensory innervation to the lacrimal gland, eyelids, and conjunctiva.
• Lactation: The secretion of milk by the mammary glands of female mammals to feed their young.
• Language: The method of human communication, either spoken or written, consisting of the use of words in a structured and conventional way.
• Language development: The process by which children come to understand and communicate language during early childhood.
• Large intestine: The last part of the digestive system in vertebrate animals, absorbing water and salts from the material that has not been digested as food, and is thus involved in the formation of feces.
• Laryngeal prominence: The lump or protrusion that is formed at the front of the neck by the angle of the thyroid cartilage surrounding the larynx, often called the Adam's apple.
• Laryngeal ventricle: A structure in the larynx that separates the vestibular and vocal folds.
• Laryngospasm: A sudden spasm of the vocal cords, temporarily blocking airflow into the lungs.
• Larynx: The hollow muscular organ forming an air passage to the lungs and holding the vocal cords in humans and other mammals; also known as the voice box.
• Lateral (anatomy): Pertaining to the side; denoting a position farther from the midline of the body or from a structure.
• Lateral geniculate nucleus: A relay center in the thalamus for the visual pathway, receiving a major sensory input from the retina.
• Latin: An ancient Italic language of the Roman Empire, used historically in the Western world and currently for scientific nomenclature.
• Latin language: Another term for Latin, emphasizing its role as a language.
• Learning: The process of acquiring new understanding, knowledge, behaviors, skills, values, attitudes, and preferences.
• Leg: The limb of the human body that extends from the groin to the ankle.
• Lichenification: The thickening and hardening of skin where it is constantly rubbed or scratched.
• Life: The condition that distinguishes animals and plants from inorganic matter, including the capacity for growth, reproduction, functional activity, and continual change preceding death.
• Ligament: A short band of tough, flexible, fibrous connective tissue that connects two bones or cartilages or holds together a joint.
• Light: Electromagnetic radiation within a certain portion of the electromagnetic spectrum, perceived by the human eye.
• Lip: Either of the two fleshy parts that form the upper and lower edges of the opening of the mouth.
• Lipids: A group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins, monoglycerides, diglycerides, triglycerides, phospholipids, and others.
• Lipophilicity: The ability of a chemical compound to dissolve in fats, oils, lipids, and nonpolar solvents such as hexane or toluene.
• Little finger: The smallest and outermost finger of the human hand, opposite the thumb.
• Liver: A large lobed glandular organ in the abdomen of vertebrates, involved in many metabolic processes.
• Long bone: Bones that are longer than they are wide and include bones of the limbs (e.g., femur, humerus).
• Longitudinal fissure: The deep groove that separates the two hemispheres of the vertebrate brain.
• Lower back pain: Discomfort located in the lower back area, a common medical condition.
• Lower extremity of femur: The part of the thigh bone that is closest to the knee.
• Lumbar vertebra: Any of the five vertebrae between the rib cage and the pelvis.
• Lumbar vertebrae: Plural form of lumbar vertebra, referring to the vertebrae in the lower back.
• Lumen (anatomy): The inside space of a tubular structure, such as an artery or intestine.
• Lung: Each of the pair of organs situated within the ribcage, consisting of elastic sacs with branching passages into which air is drawn, so that oxygen can pass into the blood and carbon dioxide be removed.
• Lung cancer: A malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung.
• Lupus erythematosus: An autoimmune disease where the body's immune system becomes hyperactive and attacks normal, healthy tissue.
• Lymph: A clear fluid that travels through the lymphatic system, carrying cells that help fight infection and disease.
• Lymph node: Small, bean-shaped structures that produce and store cells that help fight infection and disease.
• Lymphatic system: The network of vessels through which lymph drains from the tissues into the blood.
• Lymphatic vessel: A thin walled, valved structure that carries lymph.
• Lymphocyte: A type of white blood cell that is part of the immune system, including B cells, T cells, and natural killer cells.
• Lymphoid tissue: Part of the immune system, including the lymph nodes, spleen, tonsils, and thymus, where lymphocytes are produced and stored.
• Lymphoma: A group of blood cancers that develop from lymphocytes.

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• Magnesium: A chemical element and a vital mineral in the human body, important for bone health and a variety of metabolic processes.
• Major depressive disorder: A mental disorder characterized by at least two weeks of pervasive sadness or loss of interest in most activities, along with other symptoms.
• Major depressive episode: A period characterized by symptoms of major depressive disorder, including severe mood depression, lack of interest in activities, and other symptoms that impair daily functioning.
• Malabsorption: A condition in which the intestine's ability to absorb certain nutrients into the bloodstream is impaired.
• Male: Referring to the sex that produces small, mobile gametes (spermatozoa) in the context of sexual reproduction.
• Male reproductive system: The series of organs involved in producing sperm and transporting them to the female reproductive tract.
• Male urethra: The tube that carries urine from the bladder to the outside of the body, as well as semen during ejaculation.
• Malignant transformation: The process by which cells acquire the properties of cancer, including uncontrolled growth and the ability to invade other tissues.
• Malleus: A small bone in the middle ear that transmits sound vibrations from the eardrum to the incus.
• Mammal: A class of warm-blooded vertebrate animals characterized by the presence of mammary glands, which females use to feed their young with milk.
• Mammals: Plural form of mammal, referring to the group of warm-blooded animals with fur or hair and mammary glands.
• Mammary gland: The milk-producing gland of women and other female mammals.
• Mandible: The lower jawbone, the largest and strongest bone of the face.
• Mandibular prominence: The part of the embryonic jaw that gives rise to the lower jawbone or mandible.
• Mandibular symphysis: The line of fusion at the midline of the mandible, where the two halves of the mandible join.
• Marsupial: A group of mammals, commonly referred to as marsupials, in which the females typically carry and nourish their young in a pouch.
• Masseter muscle: One of the muscles that moves the jaw, primarily used for chewing.
• Maternal-fetal medicine: A branch of medicine that focuses on managing health concerns of the mother and fetus prior to, during, and shortly after pregnancy.
• Mathematics: The abstract science of number, quantity, and space, either as abstract concepts (pure mathematics) or as applied to other disciplines such as physics and engineering (applied mathematics).
• Maxilla: The upper jawbone in humans and some other animals, forming part of the nose and eye sockets.
• Median cubital vein: A superficial vein in the elbow region that is often used for venipuncture (blood draw).
• Median nerve: A major nerve of the upper limb, running down the arm to innervate parts of the hand.
• Medical billing: The process of submitting and following up on claims with health insurance companies in order to receive payment for services rendered by a healthcare provider.
• Medical biology: An interdisciplinary field that applies biological and physiological principles to clinical practice.
• Medical classification: A system of categorizing patient information for epidemiological, billing, and quality purposes.
• Medical coding: The transformation of healthcare diagnosis, procedures, medical services, and equipment into universal medical alphanumeric codes.
• Medical device: Any apparatus, instrument, machine, software, material, or other article—whether used alone or in combination, including the software intended by its manufacturer to be used specifically for diagnostic or therapeutic purposes.
• Medical diagnosis: The process of determining which disease or condition explains a person's symptoms and signs.
• Medical education: Education related to the practice of being a medical practitioner, either the initial training to become a physician or additional training thereafter.
• Medical ethics: A system of moral principles that apply values and judgments to the practice of medicine.
• Medical history: A record of a patient's background regarding health and the occurrence of any medical conditions or treatments.
• Medical imaging: The technique and process used to create images of the human body (or parts and function thereof) for clinical purposes or medical science.
• Medical laboratory: A laboratory where tests are carried out on clinical specimens to obtain information about the health of a patient.
• Medical research: The research conducted to aid and support the development of knowledge in the field of medicine.
• Medical school: An educational institution that teaches medicine and awards a professional degree for physicians and surgeons.
• Medical sign: An objective indication of some medical fact or characteristic that may be detected by a physician during a physical examination of a patient.
• Medical specialty: A branch of medical practice that is focused on a defined group of patients, diseases, skills, or philosophy; examples include cardiology, neurology, emergency medicine, and psychiatry.
• Medical students: Individuals enrolled in a medical school program to become medical doctors.
• Medical test: A procedure performed to aid in the diagnosis or detection of disease, to measure the progress or recovery from disease, or to measure the state of health.
• Medical treatment: The management and care of a patient to combat disease or disorder.
• Medication: A drug used to diagnose, cure, treat, or prevent disease.
• Medications: Plural form of medication, referring to multiple drugs used for medical treatment.
• Medicine: The science and practice of the diagnosis, treatment, and prevention of disease.
• Medulla oblongata: The lower half of the brainstem, connecting the brain to the spinal cord and controlling vital functions such as heartbeat and breathing.
• Meiosis: A type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
• Melatonin: A hormone that regulates sleep-wake cycles, produced by the pineal gland in the brain.
• Memory: The faculty by which the mind stores and remembers information.
• Meninges: The three membranes that envelop the brain and spinal cord.
• Menstrual cycle: The monthly series of changes a woman's body goes through in preparation for the possibility of pregnancy.
• Menstruation: The monthly shedding of the uterine lining in women and other female primates.
• Mental disorder: A behavioral or mental pattern that causes significant distress or impairment of personal functioning.
• Mercury (element): A chemical element with the symbol Hg and atomic number 80, known for its use in thermometers and dental amalgams, as well as its toxic effects on health.
• Metabolic: Relating to metabolism, the chemical processes that occur within a living organism to maintain life.
• Metabolic disorder: Diseases that occur due to an abnormality in the body's metabolism.
• Metabolic pathway: A series of chemical reactions occurring within a cell that lead to the conversion of one substance into another.
• Metabolism: The set of life-sustaining chemical transformations within the cells of organisms.
• Metabolite: A substance formed in or necessary for metabolism.
• Metacarpal bones: The five long bones in the hand that connect the wrist to the fingers.
• Metacarpus: The part of the hand that includes the metacarpal bones.
• Metastasis: The spread of cancer cells from the place where they first formed to another part of the body.
• Metastasize: The process by which cancer cells spread to other parts of the body.
• Metastatic breast cancer: Breast cancer that has spread beyond the breast and nearby lymph nodes to other parts of the body.
• Metatarsal bones: The long bones in the foot that connect the ankle to the toes.
• Metatarsus: The part of the foot that includes the metatarsal bones.
• Methodology: A system of methods used in a particular area of study or activity.
• Microbiology: The study of microscopic organisms, such as bacteria, viruses, archaea, fungi, and protozoa.
• Microcirculation: The circulation of the blood in the smallest blood vessels, present within organ tissues.
• Micrometre: A unit of length in the metric system, equal to one millionth of a meter, used in microbiology to measure microorganisms.
• Microvessels: The smallest blood vessels in the body, including capillaries, venules, and arterioles, involved in microcirculation.
• Middle back pain: Discomfort or pain located in the middle region of the back, often related to the thoracic spine.
• Middle ear: The portion of the ear internal to the eardrum, and external to the oval window of the cochlea, containing the malleus, incus, and stapes.
• Middle finger: The third digit of the hand, located between the index finger and the ring finger.
• Middle temporal artery: An artery that supplies blood to the temporal region of the brain.
• Midwifery: The health science and health profession that deals with pregnancy, childbirth, and the postpartum period (including care of the newborn), besides sexual and reproductive health of women throughout their lives.
• Millimeter of mercury: A unit of pressure, formerly defined as the extra pressure generated by a column of mercury one millimeter high, commonly used in blood pressure measurement.
• Mineral: A naturally occurring chemical compound, usually of crystalline form and not produced by life processes, that can contribute to various bodily functions.
• Mitosis: A part of the cell cycle in which replicated chromosomes are separated into two new nuclei, providing each new cell with a complete set of chromosomes.
• Molecular biology: The branch of biology that deals with the structure and function of the macromolecules (e.g., proteins and nucleic acids) essential to life.
• Molecule: A group of atoms bonded together, representing the smallest fundamental unit of a chemical compound that can take part in a chemical reaction.
• Mosquito-borne disease: Diseases caused by bacteria, viruses, or parasites transmitted by mosquitoes.
• Mother: A female parent.
• Motor control: The process by which humans and animals use their brain/cognition to activate and coordinate the muscles and limbs involved in the performance of a motor skill.
• Motor coordination: The combination of body movements created with the kinematic (such as spatial direction) and kinetic (force) parameters that result in intended actions.
• Motor learning: A change, resulting from practice or a novel experience, in the capability for responding. It often involves improving the smoothness and accuracy of movements.
• Mouth: The opening in the face of a person or animal, consisting of the lips and the space between them, and is the opening through which food is taken in and vocal sounds are emitted.
• Mucous gland: A gland that secretes mucus, which is a slippery secretion serving to protect and lubricate surfaces.
• Multipotent: Having the ability to develop into more than one cell type of the body but not all; a characteristic of certain stem cells.
• Muscle: A tissue composed of fibers capable of contracting to effect bodily movement.
• Muscle tone: The continuous and passive partial contraction of the muscles, or the muscle's resistance to passive stretch during resting state.
• Muscles of mastication: Muscles that are responsible for the movement of the jaw during the act of chewing food.
• Muscular system: The organ system consisting of skeletal, smooth, and cardiac muscles. It permits movement of the body, maintains posture, and circulates blood throughout the body.
• Myelin: A fatty white substance that surrounds the axon of some nerve cells, forming an electrically insulating layer. It is essential for the proper functioning of the nervous system.
• Myocardial infarction: Commonly known as a heart attack, occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle.
• Myringotomy: A surgical procedure to create a tiny incision in the eardrum to relieve pressure caused by excessive buildup of fluid, or to drain pus from the middle ear.

N

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• Nail (anatomy): A tough protective covering made of keratin at the tip of the fingers and toes in most primates.
• Nanobiotechnology: The application of nanotechnology in biological fields, focusing on the development of technologies for the manipulation of biological molecules and structures.
• Nanotechnology: The manipulation of matter on an atomic, molecular, and supramolecular scale for industrial, medical, and other purposes.
• Nasal bone: One of a pair of small oblong bones that, together, form the bridge of the nose.
• Nasal cartilages: The cartilages that support the structure of the nose, contributing to its shape and form.
• Nasal cavity: The large air-filled space above and behind the nose in the middle of the face.
• Nasal septum: The partition separating the two nostrils and the nasal cavities of the nose, composed of bone and cartilage.
• Nasopharynx: The upper part of the pharynx, connecting with the nasal cavity above the soft palate.
• Natural science: The branch of science concerned with the description, understanding, and prediction of natural phenomena, based on empirical evidence from observation and experimentation.
• Nausea: A sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit.
• Navel: The scar on the abdomen at the site of the former umbilical cord, commonly known as the belly button.
• Navicular: A small bone found in the feet and hands, named for its boat-like shape.
• Neck: The part of the body connecting the head to the rest of the body.
• Neck pain: Discomfort occurring anywhere from the bottom of the head to the top of the shoulders, which can extend to the upper back and arms as well.
• Neonatal jaundice: A common condition in newborns, characterized by yellowing of the skin and the whites of the eyes caused by high bilirubin levels.
• Nephrology: The branch of medicine that deals with the physiology and diseases of the kidneys.
• Nephrons: The functional units of the kidney, each responsible for filtering blood to produce urine.
• Nerve: A bundle of fibers that transmits electrical impulses towards and away from the brain and spinal cord, enabling communication between the central nervous system and the body.
• Nerve tract: A bundle of nerve fibers (axons) connecting nuclei of the central nervous system.
• Nervous system: The network of nerve cells and fibers that transmits nerve impulses between parts of the body, including the brain, spinal cord, and peripheral nerves.
• Neural circuit: A population of neurons interconnected by synapses to carry out a specific function when activated.
• Neurocranium: The part of the skull that encloses and protects the brain.
• Neurodegeneration: The progressive loss of structure or function of neurons, including death of neurons, often leading to neurodegenerative diseases.
• Neurodevelopmental disorder: A disorder that affects the development of the nervous system, leading to abnormal brain function and behavior.
• Neurological disorder: Any disorder of the body's nervous system, structural, biochemical, or electrical abnormalities can result in a range of symptoms.
• Neurological disorders: Plural form of neurological disorder, referring to various diseases of the central and peripheral nervous system.
• Neurology: The branch of medicine dealing with disorders of the nervous system.
• Neuron: A specialized cell transmitting nerve impulses; a nerve cell.
• Neurons: Plural form of neuron, referring to the nerve cells that form the building blocks of the nervous system.
• Neuroscience: The scientific study of the nervous system, including the brain, spinal cord, and networks of sensory nerve cells.
• Neurosurgery: The surgical discipline focused on treating those central and peripheral nervous system diseases amenable to mechanical intervention.
• Neurotransmitter: Chemicals that transmit signals across a synapse from one neuron (nerve cell) to another 'target' neuron, muscle cell, or gland cell.
• Neurovascular bundle: A structure containing a nerve, artery, and vein, often found together

O

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• Oblique muscle of auricle: A small muscle of the outer ear that acts to adjust the ear's shape slightly.
• Obstetrics: The branch of medicine and surgery concerned with childbirth and the care of women giving birth.
• Obstetrics and gynecology (Ob/Gyn): A medical specialty that encompasses both obstetrics and gynecology, focusing on women's reproductive health, childbirth, and postpartum care.
• Occipital bone: The trapezoidal-shaped bone at the lower back of the skull, important for protecting the back part of the brain and forming the base of the skull.
• Occipital lobe: The visual processing center of the mammalian brain, located in the back portion of the skull.
• Occupational therapy: A branch of health care that helps people across the lifespan to do the things they want and need to do through the therapeutic use of daily activities (occupations).
• Odor: A smell, often one that is unpleasant.
• Offspring: The product of reproduction, a new organism produced by one or more parents.
• Olecranon: The bony prominence of the elbow, on the upper end of the ulna.
• Olfaction: The sense of smell, which is part of the sensory system.
• Olfactory bulb: A neural structure of the vertebrate forebrain involved in olfaction, or the sense of smell.
• Olfactory receptor: A type of receptor cell that is responsible for detecting odors in the olfactory system.
• Olfactory system: The sensory system used for olfaction, or the sense of smell.
• Oncology: The branch of medicine that deals with the prevention, diagnosis, and treatment of cancer.
• Ophthalmic nerve: The first branch of the trigeminal nerve, which conveys sensory information from the scalp and forehead, the upper eyelid, the surface of the eyeball, and the nose.
• Ophthalmology: The branch of medicine that deals with the anatomy, physiology, and diseases of the eyeball and orbit.
• Optometry: The healthcare profession that involves examining the eyes and applicable visual systems for defects or abnormalities as well as the medical diagnosis and management of eye disease.
• Oral cavity: The mouth, or the space behind the lips and teeth that leads to the throat.
• Oral mucosa: The mucous membrane lining the inside of the mouth.
• Orbit (anatomy): The cavity or socket of the skull in which the eye and its appendages are situated.
• Organ (anatomy): A part of an organism that is typically self-contained and has a specific vital function, such as the heart or liver in humans.
• Organ system: A group of organs that work together to perform one or more functions. Each does a particular job in the body, and is made up of certain tissues.
• Organism: An individual animal, plant, or single-celled life form.
• Orthopedic surgery: The branch of surgery concerned with conditions involving the musculoskeletal system.
• Ossicle: One of the three small bones in the middle ear (the malleus, incus, and stapes) that transmit sound vibrations from the eardrum to the inner ear.
• Ossicles: Plural form of ossicle, referring to the three bones in the middle ear.
• Osteoarthritis: A type of arthritis that occurs when flexible tissue at the ends of bones wears down.
• Otitis: Inflammation of the ear, which can manifest itself as otitis externa, media, or interna depending on the part of the ear affected.
• Otitis externa: Inflammation or infection of the outer ear canal, also known as swimmer's ear.
• Otitis interna: Also known as labyrinthitis, it refers to inflammation of the inner ear structure called the labyrinth.
• Otitis media: Inflammation or infection located in the middle ear.
• Otorhinolaryngology: The medical specialty that deals with diseases and conditions of the ear, nose, and throat (ENT) region, and related areas of the head and neck.
• Outer ear: The external portion of the ear, which includes the auricle and the ear canal.
• Outpatients: Patients who receive medical treatment without being admitted to a hospital.
• Ovaries: The female reproductive organs in which ova, or eggs, are produced.
• Ovary: One of a pair of female reproductive organs that produce eggs and secrete estrogen and progesterone.
• Oviduct: The tube through which an ovum or egg passes from an ovary. Also known as the fallopian tube in humans.
• Ovotestis: A gonad having both ovarian and testicular tissue.
• Oxygen: A chemical element vital to the respiratory processes of most living cells and a component of the air.
• Oxygenated blood: Blood that has been oxygenated in the lungs and is pumped to the body by the heart.

This segment includes descriptions and links to related articles for a comprehensive glossary of medical terms starting with "O".

P

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• PH: A scale used to specify the acidity or basicity of an aqueous solution, with values ranging from 0 (acidic) to 14 (basic), and 7 being neutral.
• Pain: An unpleasant sensory and emotional experience associated with actual or potential tissue damage.
• Palate: The roof of the mouth in humans and vertebrates, separating the oral cavity from the nasal cavity.
• Palliative care: Specialized medical care for people living with a serious illness, focused on providing relief from the symptoms and stress of the illness.
• Palpation: A method of feeling with the fingers or hands during a physical examination to detect characteristics of the body, such as its texture, size, and consistency.
• Pancreas: A glandular organ in the digestive system and endocrine system of vertebrates, producing digestive enzymes and insulin, among other hormones.
• Pancreatic duct: The duct joining the pancreas to the common bile duct to supply pancreatic juice, which aids in digestion.
• Pancreatic islets (Islets of Langerhans): Regions of the pancreas containing endocrine (hormone-producing) cells.
• Pancreatic juice: A clear alkaline secretion of the pancreas, containing enzymes that aid in the digestion of proteins, carbohydrates, and fats.
• Pancreatic polypeptide: A peptide hormone involved in the regulation of pancreatic and gastrointestinal functions.
• Paralysis: The loss of muscle function in part of your body, often resulting from damage to the nervous system.
• Paramesonephric duct: Embryonic precursors to the female reproductive tract, including the fallopian tubes, uterus, and part of the vagina.
• Paranasal sinuses: Air-filled spaces within the bones of the skull and face, connected to the nasal cavity.
• Paraplegia: Paralysis affecting the legs and possibly also the trunk, but not the arms, due to spinal cord injury.
• Parasite: An organism that lives on or in a host organism and gets its food from or at the expense of its host.
• Parasitic worm (Helminth): Worm-like parasites that live and feed off living hosts, causing nutritional malabsorption, tissue damage, and other diseases.
• Parasitology: The study of parasites, their hosts, and the relationship between them.
• Parasympathetic ganglion: Clusters of neurons in the parasympathetic nervous system, part of the autonomic nervous system responsible for rest and digest functions.
• Parathyroid gland: Small endocrine glands in the neck that produce parathyroid hormone, important in calcium regulation.
• Parathyroid hormone: A hormone produced by the parathyroid glands that regulates serum calcium levels.
• Paresthesia: A sensation of tingling, pricking, or numbness of the skin with no apparent long-term physical effect.
• Parkinson's disease: A degenerative disorder of the central nervous system that often impairs the sufferer's motor skills, speech, and other functions.
• Parotid gland: The largest of the salivary glands, located near the ear, producing saliva to facilitate chewing and swallowing and aid digestion.
• Patella: The kneecap, a small bone located in front of the knee joint.
• Pathogen: An organism that causes disease in its host, such as bacteria, viruses, fungi, or parasites.
• Pathogenic bacteria: Bacteria that can cause disease in humans or other organisms.
• Pathology: The study of the causes and effects of disease or injury.
• Pectineus muscle: A flat, quadrangular muscle situated at the front part of the upper and medial aspect of the thigh.
• Pectoralis major muscle: A thick, fan-shaped muscle, situated at the chest of the human body.
• Pectoralis minor muscle: A thin, triangular muscle located beneath the pectoralis major in the chest.
• Pediatrics: The branch of medicine dealing with children and their diseases.
• Peer review: The evaluation of work by one or more people with similar competences as the producers of the work, which functions as a form of self-regulation by qualified members of a profession within the relevant field.
• Pelvic bone: A large bone structure at the base of the spine to which the legs are attached, comprising the hip bones, sacrum, and coccyx.
• Pelvic diaphragm: The muscular sheet that forms the floor of the pelvic cavity, important for organ support and maintaining continence.
• Pelvic floor: The muscles, ligaments, connective tissues, and nerves that support and control the rectum, uterus, vagina, and bladder.
• Pelvic pain: Pain perceived in the area of the pelvis, which can be a symptom of various conditions.
• Pelvis: The lower part of the torso, between the abdomen and the legs, which houses the reproductive organs and the bladder.
• Penis: The male genital organ of higher vertebrates, carrying the duct for the transfer of sperm during copulation.
• Peptide: Short chains of amino acid monomers linked by peptide (amide) bonds.
• Perception: The organization, identification, and interpretation of sensory information in order to represent and understand the environment.
• Percussion (medicine): A diagnostic technique used in medicine to detect fluid in body cavities or air in hollow organs by tapping the body's surface.
• Pericranium: The membrane that covers the outer surface of the skull.
• Perineum: The area between the anus and the scrotum or vulva.
• Perioperative medicine: The medical care of patients from the time of contemplation of surgery through the operative period to full recovery.
• Peripheral artery disease: A common circulatory problem in which narrowed arteries reduce blood flow to the limbs.
• Peripheral nervous system: The part of the nervous system that consists of the nerves and ganglia outside of the brain and spinal cord.
• Peripheral vision: The ability to see objects and movement outside of the direct line of vision.
• Peristalsis: The series of wave-like muscle contractions that moves food to different processing stations in the digestive tract.
• Personal identity: The concept you develop about yourself that evolves over the course of your life, including aspects of your life that you have no control over, such as where you grew up or the color of your skin, as well as choices you make in life, such as how you spend your time and what you believe.
• Phalanges of the hand: The bones of the fingers and thumb.
• Phalanx bone: A bone of the finger or toe.
• Pharmacology: The branch of medicine concerned with the uses, effects, and modes of action of drugs.
• Pharmacy: The science and technique of preparing, dispensing, and reviewing drugs and providing additional clinical services.
• Pharynx: The membrane-lined cavity behind the nose and mouth, connecting them to the esophagus.
• Pheromone: A chemical substance produced and released into the environment by an animal, especially a mammal or an insect, affecting the behavior or physiology of others of its species.
• Phosphate: A salt or ester of phosphoric acid, containing the phosphate ion, PO₄³⁻.
• Phospholipid: A class of lipids that are a major component of all cell membranes as they can form lipid bilayers.
• Physical examination: The process by which a medical professional investigates the body of a patient for signs of disease.
• Physical therapy: The treatment of disease, injury, or deformity by physical methods such as massage, heat treatment, and exercise rather than by drugs or surgery.
• Physician: A professional who practices medicine, which is concerned with promoting, maintaining, or restoring health through the study, diagnosis, prognosis, and treatment of disease, injury, and other physical and mental impairments.
• Physicians: Plural form of physician, referring to multiple medical doctors.
• Physiology: The scientific study of the normal functions in living systems.
• Pineal gland: A small endocrine gland in the brain, producing melatonin, a serotonin-derived hormone, which affects the modulation of sleep patterns.
• Pipecolic acidemia: A rare metabolic disorder characterized by the accumulation of pipecolic acid in the blood.
• Pituitary disease: Any disorder affecting the pituitary gland, often resulting in hormone imbalances.
• Pituitary gland: A pea-sized gland attached to the base of the brain, important in controlling growth and development and the functioning of the other endocrine glands.
• Placenta: An organ that develops in the uterus during pregnancy, providing oxygen and nutrients to and removing waste from the developing fetus through the umbilical cord.
• Placentalia: A group of mammals that includes all living mammals that have a placenta, which is most mammals, including humans.
• Plantarflexion: The movement of the foot in which the foot or toes flex downward toward the sole.
• Plantaris muscle: A thin muscle of the leg, assisting in knee flexion and plantarflexion of the foot.
• Plasma cell: A type of white blood cell that produces antibodies.
• Plastic surgery: A surgical specialty involving the restoration, reconstruction, or alteration of the human body.
• Plexus: A network of nerves or vessels in the body.
• Ploidy: The number of sets of chromosomes in a cell, or in the cells of an organism.
• Pneumonia: An inflammatory condition of the lung affecting primarily the small air sacs known as alveoli.
• Polydipsia: Excessive thirst or excess drinking.
• Polyphagia: Excessive hunger or increased appetite.
• Pons: The part of the brainstem that links the medulla oblongata and the thalamus.
• Popliteal artery: The continuation of the femoral artery in the knee, supplying blood to the knee joint and muscles in the thigh and calf.
• Popliteal vein: The vein that drains blood from the knee region into the femoral vein, becoming the femoral vein as it moves towards the hip.
• Population: A summation of all the organisms of the same group or species, which live in a particular geographical area, and have the capability of interbreeding.
• Posterior (anatomy): Located behind a part or towards the rear of a structure.
• Posterior auricular vein: A vein that drains the scalp behind the ear and empties into the external jugular vein.
• Posterior tibial artery: The artery supplying blood to the posterior compartment of the leg and plantar surface of the foot.
• Postpartum period: The period beginning immediately after the birth of a child and extending for about six weeks, during which the mother's body, including hormone levels and uterus size, returns to a non-pregnant state.
• Potential difference: The difference in electrical potential between two points, which can cause an electric current in a closed circuit.
• Pregnancy: The time during which one or more offspring develops inside a woman's uterus.
• Prehensile: Capable of grasping or holding, typically referring to parts of the body such as fingers, toes, or tails.
• Prenatal development: The process in which an embryo and later fetus develops during gestation.
• Pressure: The force applied perpendicular to the surface of an object per unit area over which that force is distributed.
• Prevalence: The proportion of a population found to be affected by a particular disease at a specific time.
• Prevention (medical): Measures taken to prevent diseases or injuries rather than curing them or treating their symptoms.
• Preventive healthcare: Measures taken for disease prevention, as opposed to disease treatment.
• Primary care: The day-to-day healthcare given by a health care provider. Typically this provider acts as the first contact and principal point of continuing care for patients within a healthcare system, and coordinates other specialist care that the patient may need.
• Primate: A member of the mammalian order Primates, including humans, apes, monkeys, and prosimians such as lemurs.
• Prion: An infectious agent composed entirely of protein material that can fold in multiple, structurally abstract ways, at least one of which is transmissible to other prion proteins, leading to disease that is similar to viral infection.
• Prism (geometry): In optics, a transparent optical element with flat, polished surfaces that refract light.
• Prognosis: The likely course of a disease or ailment.
• Pronation: The rotational movement of the forearm or foot that results in the palm or sole turning downward or backward.
• Prophylaxis: Actions taken to prevent disease, especially by specified means or against a specified disease.
• Prostate: A gland in the male reproductive system that is located just below the bladder and surrounds the urethra, producing fluid that is a component of semen.
• Protein: Large biomolecules, or macromolecules, consisting of one or more long chains of amino acid residues.
• Protein biosynthesis: The process in which cells build proteins, involving transcription of DNA to mRNA and translation of mRNA to amino acid chains, which fold into functional proteins.
• Proteins: Plural form of protein, referring to the various types of proteins found in living organisms.
• Proximal phalanges: The bones in the fingers and toes closest to the hand or foot and connected to the metacarpals or metatarsals.
• Psoas major muscle: A long fusiform muscle located on the side of the lumbar region of the vertebral column and brim of the lesser pelvis.
• Psychiatry: The medical specialty devoted to the diagnosis, prevention, and treatment of mental disorders.
• Psychology: The scientific study of the mind and behavior.
• Psychosis: An abnormal condition of the mind that results in difficulties determining what is real and what is not.
• Puberty: The period during which adolescents reach sexual maturity and become capable of reproduction.
• Pubic crest: A ridge or margin on the superior surface of the pubic bone.
• Pubic symphysis: The midline cartilaginous joint uniting the left and right pubic bones.
• Pubic tubercle: A prominent forward-projecting tubercle on the upper border of the medial portion of the superior ramus of the pubis.
• Pubis (bone): The anterior part of the pelvic bone, one of three bones that make up the pelvis.
• Public health: The science and art of preventing disease, prolonging life, and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities, and individuals.
• Puborectalis: A muscle of the pelvic floor that loops around the anorectal junction, contributing to fecal continence.
• Pulmonary alveolus: A hollow cavity found in the lung parenchyma, and is the basic unit of ventilation. Lung alveoli are the ends of the respiratory tree, branching from either alveolar sacs or alveolar ducts, which are both sites of gas exchange with the blood as well.
• Pulmonary arteries: The arteries that carry deoxygenated blood from the right side of the heart to the lungs.
• Pulmonary artery: The artery conveying blood from the right ventricle of the heart to the lungs for oxygenation.
• Pulmonary circulation: The portion of the cardiovascular system which carries deoxygenated blood away from the heart, to the lungs, and returns oxygenated blood back to the heart.
• Pulmonary vein: A vein carrying oxygenated blood from the lungs to the left atrium of the heart.
• Pulmonology: The medical specialty that deals with diseases involving the respiratory tract.
• Pulse: The throbbing of the arteries as blood is propelled through them, typically as felt in the wrists or neck.
• Pus: A thick, yellowish-white liquid produced in infected tissue, consisting of dead white blood cells and bacteria with tissue debris and serum.
• Quadriceps tendon: The tendon that connects the quadriceps femoris muscle to the patella (kneecap).
• Quality of life: The general well-being of individuals and societies, outlining negative and positive features of life.

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• Radial artery: A major artery in the forearm, supplying blood to the lateral aspect of the arm and hand.
• Radial nerve: A nerve in the human body that supplies the posterior portion of the upper limb.
• Radial styloid process: A bony projection on the distal end of the radius bone in the wrist, where it articulates with the carpal bones.
• Radial veins: Veins that accompany the radial artery and drain blood from the lateral aspect of the forearm and hand.
• Radiation: The emission or transmission of energy in the form of waves or particles through space or a material medium.
• Radioactivity: The process by which unstable atomic nuclei lose energy by emitting radiation.
• Radiology: The medical discipline that uses medical imaging to diagnose and treat diseases within the body.
• Radionuclide: A nuclide that exhibits radioactivity; used in nuclear medicine for both diagnosis and treatment.
• Radius (bone): One of the two large bones in the forearm, located on the lateral side of the forearm between the elbow and the wrist.
• Range of motion: The full movement potential of a joint, usually its range of flexion and extension.
• Rare disease: A disease that affects a small percentage of the population, often with limited treatment options.
• Rash: A change of the skin which affects its color, appearance, or texture. A rash may be localized in one part of the body, or affect all the skin.
• Reconstructive surgery: Surgery performed to restore the form and function of the body, often following trauma, disease, or birth defects.
• Rectal ampulla: An enlarged section of the rectum where feces are stored before their excretion.
• Rectum: The final straight portion of the large intestine in humans and some other mammals, terminating in the anus.
• Rectus abdominis muscle: A paired muscle running vertically on each side of the anterior wall of the human abdomen, involved in moving the body between the ribcage and the pelvis.
• Red blood cell: A cell in the blood that takes up oxygen in the lungs and delivers it to cells elsewhere in the body.
• Refractive error: A problem with focusing light accurately onto the retina due to the shape of the eye, resulting in a blurred image.
• Regressive autism: A condition characterized by a child who seems to develop typically but then starts to lose speech and social skills, typically around the age of 2 years.
• Relay: In neurology, refers to the process by which one neuron communicates with another neuron in a neural pathway.
• Renal artery: The blood vessel that carries oxygenated blood to the kidneys.
• Renal function: The state of how well the kidneys perform their functions of excreting waste products and regulating blood pressure, electrolyte balance, and red blood cell production.
• Renal vein: The vein that carries deoxygenated blood away from the kidney toward the heart.
• Reproduction: The biological process by which new individual organisms are produced.
• Reproductive system: The sex organs within an organism which work together for the purpose of sexual reproduction.
• Reptiles: A class of cold-blooded, egg-laying vertebrates that includes snakes, lizards, crocodiles, turtles, and tortoises.
• Residency (medicine): A stage of graduate medical training wherein a physician practices medicine under the supervision of a fully licensed physician.
• Respiration (physiology): The process by which living organisms take in oxygen and expel carbon dioxide, involving the respiratory system.
• Respiratory arrest: The cessation of breathing due to failure of the lungs to function effectively.
• Respiratory epithelium: The protective mucosal lining of the respiratory tract, which functions in warming, moistening, and filtering the air entering the lungs.
• Respiratory rate: The number of breaths a person takes per minute, an important vital sign.
• Respiratory system: The series of organs responsible for taking in oxygen and expelling carbon dioxide in living organisms.
• Respiratory tract: The passageway that makes up the respiratory system, through which air and gases are moved in and out of the lungs.
• Retina: The thin layer of tissue that lines the back of the eye on the inside, receiving light that the lens has focused, converting the light into neural signals, and sending these signals to the brain for visual recognition.
• Retromandibular vein: A vein located within the parotid gland that drains blood from the temporal region of the head.
• Retroperitoneal space: An anatomical space in the abdominal cavity behind the peritoneum.
• Rheumatic fever: An inflammatory disease that can develop as a complication of inadequately treated strep throat or scarlet fever, causing inflammation in the heart, joints, skin, and brain.
• Rheumatic heart disease: A condition in which the heart valves have been permanently damaged by rheumatic fever.
• Rheumatology: The branch of medicine that deals with the diagnosis and treatment of rheumatic diseases, which affect the joints, muscles, and bones.
• Rhinorrhea: The medical term for a runny nose, an excess drainage of a mixture of mucus and watery substance from the nasal mucous membranes.
• Rib: One of a set of long, curved bones which form the rib cage, protecting the chest cavity and the organs therein.
• Rib cage: The bony structure surrounding the chest, composed of the ribs and the sternum, providing protection for the heart and lungs.
• Right-handed: A preference for using the right hand for tasks such as writing and throwing.
• Ring finger: The fourth proximal digit of the human hand, located between the middle finger and the little finger.
• Risk factor: Anything that increases an individual's likelihood of developing a disease or injury.
• Rod cell: A type of photoreceptor in the retina that is responsible for vision at low light levels.
• Root of the lung: The complex structure by which the lungs are attached to the trachea.

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• Saccule: A small, fluid-filled sac or cavity in the vestibular system of the inner ear, contributing to the sensation of balance.
• Sacroiliac joint: The joint between the sacrum, at the base of the spine, and the iliac bones of the pelvis, which are connected by strong ligaments.
• Sacrum: A large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, formed by the fusion of five vertebrae.
• Sadness: An emotional state characterized by feelings of disappointment, grief, or hopelessness.
• Saliva: The watery and usually frothy substance produced in the mouths of humans and most other animals, produced by salivary glands and aiding in digestion.
• Salivary gland: Any of several exocrine glands that produce saliva to aid in digestion and oral health.
• Saphenous nerve: A branch of the femoral nerve that innervates the skin of the inner leg and foot.
• Sartorius muscle: The longest muscle in the human body, running down the length of the thigh; its action is to flex the thigh and leg.
• Scalp: The skin covering the head, excluding the face.
• Scapula: The shoulder blade, a large, flat, triangular bone located in the upper back.
• Schlemm's canal: A circular lymphatic-like vessel in the eye that collects aqueous humor from the anterior chamber and delivers it into the bloodstream.
• Schwann cell: A type of glial cell in the peripheral nervous system that wraps around axons, forming the myelin sheath.
• Sciatic nerve: The largest nerve in the human body, extending from the lower end of the spinal cord, down the back of the thigh, and dividing near the knee into branches that go to the feet.
• Science: The systematic enterprise that builds and organizes knowledge in the form of testable explanations and predictions about the universe.
• Sclera: The white part of the eye, a tough covering that protects the eyeball.
• Scrotum: The pouch of skin containing the testicles in males.
• Sebaceous gland: A small gland in the skin that secretes a lubricating oily matter (sebum) into the hair follicles to lubricate the skin and hair.
• Sebum: The oily secretion of the sebaceous glands, helping to keep skin and hair moisturized.
• Second messenger: A molecule that relays signals received at receptors on the cell surface to target molecules inside the cell, within the cytoplasm or nucleus.
• Secondary care: Medical care provided by a specialist or facility upon referral by a primary care physician, involving advanced medical investigation and treatment.
• Secosteroid: A type of steroid with a "broken" ring, involved in biological processes such as vitamin D synthesis.
• Self-esteem: An individual's subjective evaluation of their own worth.
• Self-image: The idea, conception, or mental image one has of oneself.
• Semicircular canal: One of three looped structures within the inner ear that are responsible for maintaining balance.
• Seminal vesicle: One of two small glands located behind the bladder in males that secrete fluid that partly composes the semen.
• Sense: A faculty by which the body perceives an external stimulus; one of the faculties of sight, smell, hearing, taste, and touch.
• Sense organ: An organ of the body which responds to external stimuli by conveying impulses to the sensory nervous system.
• Sensorineural hearing loss: A type of hearing loss resulting from damage to the inner ear or the nerve pathways from the inner ear to the brain.
• Sensory nerve: A nerve that carries sensory information toward the central nervous system.
• Sensory nervous system: The part of the nervous system responsible for processing sensory information.
• Sensory perception: The neurological processes by which we perceive our environment.
• Sensory processing: The way the nervous system receives messages from the senses and turns them into appropriate motor and behavioral responses.
• Sensory system: The part of the nervous system responsible for processing sensory information.
• Seromucous gland: A type of gland that secretes both mucus and a watery fluid.
• Serous gland: A gland that produces a watery, protein-rich fluid secretion.
• Serratus anterior muscle: A muscle that originates on the surface of the upper eight or nine ribs and inserts along the entire anterior

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• Talus bone - The talus bone, also known as the astragalus, is a bone in the foot that articulates with the tibia and fibula, forming the ankle joint.
• Tarsus (skeleton) - The tarsus is the cluster of seven bones in the foot situated between the leg and the metatarsus.
• Taste - Taste refers to the perception of flavors through the gustatory system.
• Taste bud - Taste buds are sensory organs on the tongue and other parts of the mouth that detect taste.
• Taste receptor - Taste receptors are proteins that detect different flavors and are located on taste cells within taste buds.
• Temporal bone - The temporal bone is a large, irregular bone situated on the side of the skull.
• Temporal fossa - The temporal fossa is a shallow depression on the side of the skull that contains the temporal muscle.
• Temporal muscle - The temporal muscle is one of the muscles of mastication, responsible for jaw movement.
• Temporalis - The temporalis muscle is a large muscle of mastication that aids in closing the jaw during chewing.
• Tendon - A tendon is a fibrous connective tissue that connects muscle to bone.
• Tendons - Tendons are fibrous tissues that connect muscles to bones, providing stability and facilitating movement.
• Teratology - Teratology is the study of abnormalities of physiological development.
• Teres major - The teres major is a muscle of the upper limb located in the back of the shoulder.
• Teres major muscle - The teres major muscle is a muscle of the upper limb that helps rotate the arm.
• Tertiary care - Tertiary care refers to specialized medical care provided by specialists or facilities equipped with advanced medical technology.
• Testes - The testes are the male reproductive glands responsible for producing sperm and testosterone.
• Testicle - A testicle is one of the two male reproductive glands located in the scrotum.
• Tetraplegia - Tetraplegia, also known as quadriplegia, is paralysis caused by injury to the spinal cord, resulting in partial or total loss of use of all four limbs and the torso.
• Tetrapod - A tetrapod is a vertebrate animal with four limbs or leg-like appendages.
• Thalamus - The thalamus is a part of the brain that relays sensory information to the cerebral cortex.
• Therapeutic - Therapeutic refers to the treatment or management of a disease or medical condition.
• Therapy - Therapy refers to the treatment of a disease or medical condition through various methods.
• Thermodynamics - Thermodynamics is the branch of physics that deals with the relationships between heat, work, and energy.
• Thermoregulation - Thermoregulation is the process by which organisms maintain their internal body temperature within a tolerable range.
• Thiamine - Thiamine, also known as vitamin B1, is a water-soluble vitamin essential for the body's metabolism.
• Thiamine deficiency - Thiamine deficiency is a lack of thiamine in the body, which can lead to various health problems, including beriberi.
• Thigh - The thigh is the portion of the leg between the hip and the knee.
• Thoracic diaphragm - The thoracic diaphragm, commonly referred to as the diaphragm, is a sheet of muscle that separates the thoracic and abdominal cavities, essential for breathing.
• Thoracic spinal nerve 1 - Thoracic spinal nerve 1 is one of the spinal nerves emerging from the thoracic region of the spinal cord.
• Thoracoepigastric vein - The thoracoepigastric vein is a vein that drains blood from the abdominal wall into the superior epigastric vein.
• Thorax - The thorax, or chest, is the region of the body between the neck and the abdomen, containing the heart, lungs, and other vital organs.
• Throat - The throat is the anatomical structure that connects the mouth and nasal passages to the esophagus and trachea.
• Thrombosis - Thrombosis is the formation of a blood clot within a blood vessel, obstructing blood flow.
• Thumb - The thumb is the first digit of the hand, opposite the other four fingers.
• Thymus - The thymus is a lymphoid organ located behind the sternum and is essential for the development of the immune system.
• Thyroid - The thyroid is a butterfly-shaped gland in the neck that produces hormones regulating metabolism.
• Thyroid cartilage - The thyroid cartilage, also known as the Adam's apple, is a hyaline cartilage structure that forms the prominence in the neck.
• Thyroid gland - The thyroid gland is an endocrine gland in the neck responsible for producing hormones that regulate metabolism.
• Thyroid ima artery - The thyroid ima artery is an artery that occasionally arises from the brachiocephalic trunk or the aorta and supplies blood to the thyroid gland.
• Thyroiditis - Thyroiditis is inflammation of the thyroid gland, which can result in hyperthyroidism or hypothyroidism.
• Tibia - The tibia, or shinbone, is the larger and stronger of the two bones in the lower leg.
• Tibialis anterior muscle - The tibialis anterior muscle is a muscle located in the front of the leg that helps dorsiflex the foot.
• Tibialis posterior muscle - The tibialis posterior muscle is a muscle located in the back of the leg that helps invert and plantarflex the foot.
• Tissue (biology) - In biology, tissue refers to a group of cells with similar structure and function.
• Toe - Toes are the digits of the foot, typically numbered one through five and corresponding to the phalanges.
• Toll-like receptor - Toll-like receptors are a class of proteins involved in the innate immune system's recognition of pathogens.
• Tongue - The tongue is a muscular organ in the mouth that aids in chewing, swallowing, and speech production.
• Tooth - A tooth is a hard, calcified structure in the mouth used for biting and chewing food.
• Tophus - A tophus is a deposit of crystallized uric acid in tissues, commonly associated with gout.
• Torso - The torso, or trunk, is the main part of the body, excluding the head, arms, and legs.
• Toxicology - Toxicology is the study of the adverse effects of chemicals on living organisms.
• Trachea - The trachea, or windpipe, is a tubular structure in the neck that carries air to and from the lungs.
• Transitional epithelium - Transitional epithelium is a type of tissue found in the urinary system that can stretch and recoil without damage.
• Transplant rejection - Transplant rejection occurs when the recipient's immune system attacks and damages a transplanted organ or tissue.
• Transverse abdominal muscle - The transverse abdominal muscle is a muscle layer of the anterior and lateral abdominal wall that aids in core stability.
• Trapezius muscle - The trapezius muscle is a large, triangular muscle of the upper back and neck responsible for shoulder movement and stability.
• Trapezoid - The trapezoid is a small bone in the wrist, situated between the trapezium and the capitate.
• Trauma (medicine) - Trauma in medicine refers to physical injury or wound caused by an external force or violence.
• Treponema pallidum - Treponema pallidum is the bacterium that causes syphilis, a sexually transmitted infection.
• Triceps brachii muscle - The triceps brachii muscle is a three-headed muscle located on the back of the upper arm, responsible for extending the elbow.
• Trigeminal ganglion - The trigeminal ganglion is a sensory ganglion of the trigeminal nerve responsible for transmitting sensory information from the face to the brain.
• Trigeminal nerve - The trigeminal nerve is the fifth cranial nerve responsible for sensation in the face and motor functions such as chewing.
• Tumor - A tumor is an abnormal mass of tissue caused by uncontrolled cell growth and division.
• Turbulent flow - Turbulent flow is a type of fluid flow characterized by chaotic, irregular motion.
• Tympanic cavity - The tympanic cavity is a hollow space in the temporal bone of the skull that houses the middle ear structures.
• Tympanostomy tube - A tympanostomy tube, also known as a ventilation tube or ear tube, is a small tube inserted into the eardrum to ventilate the middle ear and prevent fluid accumulation.

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• Ulcer - An ulcer is a sore or lesion that develops on the skin or mucous membranes, often caused by infection or inflammation.
• Ulna - The ulna is one of the two bones in the forearm, located on the medial side.
• Ulnar artery - The ulnar artery is an artery that supplies blood to the forearm and hand, running along the ulna.
• Ulnar nerve - The ulnar nerve is a nerve that supplies sensation to the forearm and hand and controls certain muscles of the hand.
• Ulnar veins - Ulnar veins are veins that accompany the ulnar artery and drain blood from the forearm and hand.
• Umbilical artery - The umbilical artery is a fetal blood vessel that carries deoxygenated blood from the fetus to the placenta.
• Umbilical cord - The umbilical cord is a flexible cord-like structure connecting the fetus to the placenta in utero, providing nutrients and oxygen.
• Unconsciousness - Unconsciousness is a state of being unaware of one's surroundings and unable to respond to stimuli.
• Unilateral hearing loss - Unilateral hearing loss refers to hearing impairment in one ear.
• United States - The United States, often abbreviated as U.S. or USA, is a country primarily located in North America.
• Upper arm - The upper arm is the region of the arm between the shoulder and the elbow.
• Upper extremity - The upper extremity refers to the limb comprising the arm, forearm, wrist, and hand.
• Upper eyelid - The upper eyelid is the upper fold of skin covering the eye when closed.
• Upper limb - The upper limb refers to the limb comprising the arm, forearm, wrist, and hand.
• Upper respiratory tract - The upper respiratory tract consists of the nasal cavity, pharynx, and larynx.
• Urate nephropathy - Urate nephropathy is kidney damage caused by the deposition of uric acid crystals.
• Ureter - A ureter is a muscular tube that transports urine from the kidneys to the urinary bladder.
• Ureters - Ureters are muscular tubes that carry urine from the kidneys to the urinary bladder.
• Urethra - The urethra is a tube that carries urine from the bladder to the outside of the body during urination.
• Urethral sphincter - A urethral sphincter is a muscle that controls the flow of urine from the bladder through the urethra.
• Urethral sphincters - Urethral sphincters are muscles that control the flow of urine from the bladder through the urethra.
• Urinary bladder - The urinary bladder is a hollow, muscular organ that stores urine before it is expelled from the body during urination.
• Urinary meatus - The urinary meatus is the external opening of the urethra, through which urine is expelled from the body.
• Urinary system - The urinary system, also known as the renal system, is the organ system responsible for producing, storing, and eliminating urine.
• Urinary tract - The urinary tract is the anatomical pathway through which urine flows from the kidneys to the outside of the body.
• Urination - Urination, also known as micturition, is the process of expelling urine from the urinary bladder through the urethra.
• Urine - Urine is a liquid waste product excreted by the kidneys and expelled from the body during urination.
• Urogenital sinus - The urogenital sinus is a structure in embryonic development that gives rise to the urinary and reproductive systems.
• Urology - Urology is the branch of medicine that focuses on the diagnosis and treatment of disorders of the urinary tract and male reproductive system.
• Urothelium - Urothelium, also known as transitional epithelium, is a type of tissue that lines the urinary tract.
• Uterine cavity - The uterine cavity is the inner space within the uterus where a fertilized egg implants and develops during pregnancy.
• Uterus - The uterus, also known as the womb, is the organ in which fetal development occurs during pregnancy.

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• Vaccine - A vaccine is a biological preparation that provides active acquired immunity to a particular infectious disease.
• Vagina - The vagina is a muscular canal in female mammals that extends from the vulva to the cervix and serves as the birth canal and as the exit for menstrual flow.
• Vaginal bleeding - Vaginal bleeding refers to bleeding from the vagina that is not part of a menstrual period.
• Valvular heart disease - Valvular heart disease is a condition characterized by dysfunction or damage to one or more of the heart's valves.
• Vas deferens - The vas deferens, also known as the ductus deferens, is a duct in the male reproductive system that transports sperm from the epididymis to the ejaculatory duct.
• Vascular layer - The vascular layer, also known as the uvea or uveal tract, is the middle layer of the eye containing blood vessels.
• Vascular resistance - Vascular resistance is the resistance to blood flow within the blood vessels, which affects blood pressure.
• Vastus intermedius muscle - The vastus intermedius muscle is one of the four quadriceps muscles located in the anterior compartment of the thigh.
• Vastus lateralis muscle - The vastus lateralis muscle is one of the four quadriceps muscles located on the lateral side of the thigh.
• Vein - A vein is a blood vessel that carries blood towards the heart, typically carrying deoxygenated blood.
• Veins - Veins are blood vessels that carry blood towards the heart, typically carrying deoxygenated blood.
• Venae comitantes - Venae comitantes are paired veins that accompany arteries and share a similar course and function.
• Venous thrombosis - Venous thrombosis is the formation of a blood clot within a vein, often occurring in the deep veins of the legs (deep vein thrombosis).
• Ventral - Ventral refers to the front or anterior side of the body or any structure.
• Ventricle (heart) - A ventricle is a chamber of the heart that pumps blood out of the heart and into the circulatory system.
• Venule - A venule is a small blood vessel that collects blood from capillaries and transports it to larger veins.
• Vermiform - Vermiform means worm-shaped or resembling a worm.
• Vertebrae - Vertebrae are the individual bones that make up the vertebral column, or spine.
• Vertebral column - The vertebral column, also known as the spine or backbone, is a series of vertebrae that encloses and protects the spinal cord.
• Vertebrate - A vertebrate is an animal with a backbone or spinal column.
• Vertebrates - Vertebrates are animals with a backbone or spinal column.
• Vestibular fold - The vestibular fold, also known as the false vocal cord, is a pair of folds of mucous membrane in the larynx.
• Veterinarian - A veterinarian is a medical professional who specializes in the health and treatment of animals.
• Viral disease - A viral disease is a disease caused by a virus, a small infectious agent that replicates inside living cells.
• Virology - Virology is the branch of science that deals with the study of viruses and viral diseases.
• Virus - A virus is a microscopic infectious agent that can only replicate inside the cells of a living organism.
• Visible spectrum - The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye.
• Visual acuity - Visual acuity is the clarity or sharpness of vision, typically measured using a Snellen chart.
• Visual cortex - The visual cortex is the part of the brain responsible for processing visual information received from the eyes.
• Visual field test - A visual field test is an examination that measures the range of vision, including peripheral vision and central vision.
• Visual perception - Visual perception is the ability to interpret and understand visual information from the environment.
• Vital signs - Vital signs are measurements of essential body functions, including temperature, pulse, respiration rate, and blood pressure.
• Vitamin D - Vitamin D is a group of fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate.
• Vitrectomy - Vitrectomy is a surgical procedure to remove some or all of the vitreous humor from the eye.
• Vitreous body - The vitreous body, or vitreous humor, is the clear gel that fills the space between the lens and the retina of the eye.
• Vitreous humor - The vitreous humor, or vitreous body, is the clear gel that fills the space between the lens and the retina of the eye.
• Vocal fold - A vocal fold, also known as the vocal cord, is a pair of muscular folds in the larynx responsible for producing sound.
• Voiding - Voiding is the process of emptying the bladder during urination.
• Vulva - The vulva is the external part of the female genitalia, including the labia, clitoris, and vaginal opening.
• Waist - The waist is the narrowing of the body between the rib cage and the hips.
• Wart - A wart is a small, rough growth on the skin caused by the human papillomavirus (HPV).
• Weber test - The Weber test is a screening test for hearing that evaluates bone conduction in cases of unilateral hearing loss.
• Well-being - Well-being refers to a state of being comfortable, healthy, and happy.
• Wernicke's area - Wernicke's area is a region of the brain involved in the comprehension of language.
• Wernicke encephalopathy - Wernicke encephalopathy is a neurological disorder caused by thiamine deficiency, characterized by confusion, ataxia, and eye movement abnormalities.
• West Nile virus - The West Nile virus is a virus transmitted by mosquitoes that can cause illness ranging from mild fever to severe neurological symptoms.
• Wheezing - Wheezing is a high-pitched whistling sound produced during breathing, typically due to narrowed airways.
• White blood cell - White blood cells, also known as leukocytes, are cells of the immune system involved in defending the body against infections and foreign substances.
• White matter - White matter is a type of nervous tissue in the central nervous system consisting mostly of myelinated axons.
• Woman - A woman is an adult human female.
• Working memory - Working memory is a system for temporarily storing and managing information required for complex cognitive tasks such as learning, reasoning, and comprehension.
• World Health Organization - The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health.
• Wrist - The wrist is the joint connecting the hand to the forearm.
• X-rays - X-rays are a form of electromagnetic radiation used in medical imaging to produce images of the inside of the body.
• Xiphoid process - The xiphoid process is a small, cartilaginous extension of the lower part of the sternum.
• Yaws - Yaws is a tropical infection caused by the bacterium Treponema pallidum subspecies pertenue, characterized by skin lesions and bone deformities.
• Yellow - Yellow is the color between orange and green on the spectrum of visible light.
• Yellow fever - Yellow fever is a viral hemorrhagic fever transmitted by infected mosquitoes, characterized by jaundice and fever.
• Yellow fever virus - The yellow fever virus is the causative agent of yellow fever, a viral hemorrhagic fever transmitted by mosquitoes.
• Zellweger syndrome - Zellweger syndrome is a rare genetic disorder characterized by the absence or dysfunction of peroxisomes in cells.
• Zika virus - The Zika virus is a mosquito-borne virus that can cause birth defects such as microcephaly in infants born to infected mothers.
• Zoonosis - A zoonosis is a disease that can be transmitted from animals to humans.
• Zygomatic bone - The zygomatic bone, also known as the cheekbone, is a facial bone that forms the prominence of the cheek.

See Also

• Glossary of medicine
• Medical terminology
• Medical literature
• Medical education

External links

• Medical encyclopedia article on Medical dictionary
• Wikipedia's article - Medical dictionary

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