Body fluid

Body Fluid

Diagram showing the cellular fluid content.

Body fluid refers to the liquids that are found within the bodies of living organisms. These fluids play crucial roles in maintaining homeostasis, facilitating biochemical reactions, and transporting nutrients and waste products.

Types of Body Fluids

Body fluids can be broadly categorized into two main types: intracellular fluid and extracellular fluid.

Intracellular Fluid

Intracellular fluid (ICF) is the fluid contained within the cells. It accounts for about two-thirds of the total body water in humans. The primary components of intracellular fluid include water, dissolved ions, small molecules, and large, water-soluble molecules such as proteins.

Extracellular Fluid

Extracellular fluid (ECF) is the fluid outside the cells. It is further divided into several subcategories:

• Interstitial fluid: This fluid surrounds the cells and provides a medium for the exchange of substances between the blood and the cells.
• Blood plasma: The liquid component of blood, which carries cells and proteins throughout the body.
• Lymph: A clear fluid that travels through the lymphatic system and is involved in immune responses.
• Cerebrospinal fluid: A clear fluid found in the brain and spinal cord, providing cushioning and protection.
• Synovial fluid: A viscous fluid found in the cavities of synovial joints, reducing friction between the articular cartilage of synovial joints during movement.

Functions of Body Fluids

Body fluids serve several vital functions, including:

• Transport: They transport nutrients, gases, and waste products to and from cells.
• Regulation: They help regulate body temperature and pH levels.
• Protection: Fluids like cerebrospinal fluid and synovial fluid provide cushioning and protection to vital organs and joints.
• Lubrication: Fluids such as saliva and mucus lubricate surfaces to facilitate movement and reduce friction.

Composition of Body Fluids

The composition of body fluids varies depending on their location and function. However, they generally contain:

• Water: The primary component, making up about 60% of the human body weight.
• Electrolytes: Such as sodium, potassium, calcium, and chloride, which are essential for nerve function and muscle contraction.
• Proteins: Including enzymes and hormones that facilitate biochemical reactions.
• Nutrients: Such as glucose and amino acids, which are necessary for cellular metabolism.

Related Pages

• Homeostasis
• Electrolyte
• Osmosis
• Acid-base balance