Upper limb

Upper Limb

The upper limb of the human body, also known as the upper extremity, is a complex structure that includes the shoulder, arm, forearm, and hand. It is primarily responsible for a wide range of movements and functions, including manipulation, sensation, and interaction with the environment.

Bones of the upper limb

Anatomy

The upper limb is composed of several key anatomical regions:

Pectoral Girdle

The pectoral girdle connects the upper limb to the trunk and consists of the clavicle and scapula. These bones provide attachment points for muscles and support the arm.

Diagram of the pectoral girdle

Bones

The bones of the upper limb include the humerus in the arm, the radius and ulna in the forearm, and the carpals, metacarpals, and phalanges in the hand.

Bones with articular cartilage

Joints

The major joints of the upper limb include the shoulder joint, elbow joint, wrist joint, and the joints of the hand. These joints allow for a wide range of motion and dexterity.

Muscles

The muscles of the upper limb are responsible for movement and stability. They include the muscles of the shoulder, arm, forearm, and hand.

Muscles of the upper limb

Arm Muscles

The arm contains major muscles such as the biceps brachii, triceps brachii, and brachialis. These muscles are involved in flexion and extension of the elbow.

Superficial muscles of the arm

Nerves

The brachial plexus is a network of nerves that innervates the upper limb. It provides motor and sensory innervation to the muscles and skin.

Nerves of the upper limb

Blood Supply

The blood supply to the upper limb is primarily provided by the subclavian artery, which continues as the axillary artery and then the brachial artery. These arteries branch into smaller vessels that supply the forearm and hand.

Arteries of the upper limb

Function

The upper limb is essential for a variety of functions, including:

• Manipulation: The hand and fingers are capable of precise movements, allowing for tasks such as writing, typing, and grasping objects.
• Sensation: The skin of the upper limb contains sensory receptors that provide information about touch, temperature, and pain.
• Movement: The upper limb can perform a wide range of movements, including flexion, extension, abduction, adduction, and rotation.

Clinical Significance

Injuries and conditions affecting the upper limb can significantly impact daily activities. Common issues include fractures, dislocations, tendonitis, and nerve compression syndromes such as carpal tunnel syndrome.

3D animation of the human wrist

Related Pages

• Lower limb
• Skeletal system
• Muscular system
• Nervous system