Upper Limb Structure and Joints

Upper Limb Structure

• The upper limb consists of the scapula, humerus, radius, ulna, carpals, metacarpals, and phalanges.
• The scapula is a flat, triangular bone that forms the posterior wall of the thoracic cage.
• The humerus is the longest bone in the upper limb, extending from the scapula to the elbow.

Joints of the Upper Limb

• Scapulothoracic joint: a plane joint between the scapula and thoracic cage.
• Glenohumeral joint: a ball-and-socket joint between the scapula and humerus.
• Elbow joint: a hinge joint between the humerus and radius/ulna.
• Radioulnar joints: pivot joints between the radius and ulna.
• Wrist joint: a condyloid joint between the radius/ulna and carpals.
• Metacarpophalangeal joints: condyloid joints between the metacarpals and phalanges.
• Interphalangeal joints: hinge joints between the phalanges.

Muscles of the Upper Limb

• Deltoid: abducts the arm
• Biceps brachii: flexes the forearm
• Triceps brachii: extends the forearm
• Forearm muscles: flex, extend, and rotate the wrist and fingers
• Intrinsic muscles of the hand: flex, extend, and rotate the fingers

Nerve Supply of the Upper Limb

• Brachial plexus: a network of nerves formed by the C5-T1 spinal nerves.
• Axillary nerve: supplies the deltoid muscle.
• Radial nerve: supplies the extensor muscles of the forearm.
• Median nerve: supplies the flexor muscles of the forearm and hand.
• Ulnar nerve: supplies the flexor carpi ulnaris and flexor digitorum profundus muscles.

Blood Supply of the Upper Limb

• Subclavian artery: the main artery of the upper limb.
• Axillary artery: a continuation of the subclavian artery.
• Brachial artery: a branch of the axillary artery.
• Radial and ulnar arteries: branches of the brachial artery that form the palmar arches.

Upper Limb Structure

• The upper limb consists of scapula, humerus, radius, ulna, carpals, metacarpals, and phalanges.
• Scapula is a flat, triangular bone forming the posterior wall of the thoracic cage.
• Humerus is the longest bone in the upper limb, extending from the scapula to the elbow.

Joints of the Upper Limb

• Scapulothoracic joint is a plane joint between the scapula and thoracic cage.
• Glenohumeral joint is a ball-and-socket joint between the scapula and humerus.
• Elbow joint is a hinge joint between the humerus and radius/ulna.
• Radioulnar joints are pivot joints between the radius and ulna.
• Wrist joint is a condyloid joint between the radius/ulna and carpals.
• Metacarpophalangeal joints are condyloid joints between the metacarpals and phalanges.
• Interphalangeal joints are hinge joints between the phalanges.

Muscles of the Upper Limb

• Deltoid muscle abducts the arm.
• Biceps brachii muscle flexes the forearm.
• Triceps brachii muscle extends the forearm.
• Forearm muscles flex, extend, and rotate the wrist and fingers.
• Intrinsic muscles of the hand flex, extend, and rotate the fingers.

Nerve Supply of the Upper Limb

• Brachial plexus is a network of nerves formed by the C5-T1 spinal nerves.
• Axillary nerve supplies the deltoid muscle.
• Radial nerve supplies the extensor muscles of the forearm.
• Median nerve supplies the flexor muscles of the forearm and hand.
• Ulnar nerve supplies the flexor carpi ulnaris and flexor digitorum profundus muscles.

Blood Supply of the Upper Limb

• Subclavian artery is the main artery of the upper limb.
• Axillary artery is a continuation of the subclavian artery.
• Brachial artery is a branch of the axillary artery.
• Radial and ulnar arteries are branches of the brachial artery that form the palmar arches.