Ch._16-17_Axilla_and_Brachial_Plexus_and_Scapular_Region--2025__1_

Axilla

Also known as the armpit; it has a base and four walls.

Brachial Plexus

A network of nerves that supplies all structures in the upper limb.

Musculocutaneous Nerve

Innervates the coracobrachialis, biceps, and brachialis muscles.

Radial Nerve

Innervates the triceps, brachioradialis, and extensor muscles of the forearm.

Median Nerve

Innervates most of the flexors of the forearm and the intrinsic muscles of the hand.

Ulnar Nerve

Innervates the flexor carpi ulnaris and the medial half of the flexor digitorum profundus.

Deltoid Muscle

A muscle that forms the rounded contour of the shoulder; has three heads.

Rotator Cuff

A group of four muscles that stabilize the glenohumeral joint.

Erb's Palsy

Injury to the brachial plexus affecting the C5-C6 nerve roots, leading to loss of shoulder function.

Scapula

A flat triangular bone also known as the shoulder blade.

Brachial Artery

The continuation of the axillary artery that supplies blood to the arm.

Axillary Vein

The vein that is medial to the axillary artery and drains into the subclavian vein.

Brachial Plexus Injury

Injury caused by forceful movements that affect the nerves of the brachial plexus.

Triangle of Auscultation

A small triangle gap in the musculature, good for listening to lung sounds.

Subscapularis Muscle

An internal rotator of the humerus located beneath the scapula.

Teres Major

A muscle that aids the latissimus dorsi in internal rotation and adduction of the humerus.

Nerve Root

Emerges from the spinal canal and contributes to the formation of the brachial plexus.

Cervical Nerve Roots

Roots C5-T1 are involved in forming the brachial plexus.

Thoracodorsal Nerve

Provides motor innervation to the latissimus dorsi muscle.

Accessory Nerve

Motor nerve that innervates the trapezius muscle, not part of the brachial plexus.

Lateral Cord

Part of the brachial plexus that gives rise to lateral branches including the musculocutaneous nerve.

Medial Cord

Part of the brachial plexus that contributes to the ulnar nerve.

Posterior Cord

Part of the brachial plexus that gives rise to the radial and axillary nerves.

Sensory Distribution

The area of skin innervated by a specific nerve.

Clinical Loss

The functional loss due to nerve injury or damage.