What Is the Axillary Nerve?

It is a branch of the posterior brachial plexus, containing the fibers of the anterior branch of the 5th to 6th cervical nerves. After initiation from the posterior brachial plexus, it accompanies the posterior brachial artery and passes through the four-hole foreward, and runs around the humeral surgical neck in the triangle. Deep side of muscle. Branches along the way are distributed to the deltoid muscle, small round muscle and the outer skin of the arm.

It is a branch of the posterior brachial plexus, containing the fibers of the anterior branch of the 5th to 6th cervical nerves. After initiation from the posterior brachial plexus, it accompanies the posterior brachial artery and passes through the four-hole foreward, and runs around the humeral surgical neck in the triangle Deep side of muscle. Branches along the way are distributed to the deltoid muscle, small round muscle and the outer skin of the arm.

Chinese name

Axillary nerve

Foreign name

axillary nerve

Make up

Fibers of the anterior branch of the 5th and 6th cervical nerves

Send out

Posterior brachial plexus

Axillary nerve overview

The main manifestations of axillary nerve trunk injury are: the arm cannot be abducted; the external force of the arm rotation is weakened; skin sensory disorders in the shoulder and the upper third of the lateral area of the arm; when the axillary nerve injury is long, due to deltoid muscle atrophy, the shoulder The bones protruded and the shoulders lost their rounded appearance.

Axillary nerve anatomy

The axillary nerve (C ₅ ~ C ₆ ) is one of the short and thick end branches of the brachial plexus. The axillary nerve is located behind the axillary artery and the outer side of the radial nerve. When it descends to the lower edge of the subscapularis muscle, it accompanies the posterior brachial artery through the four-sided space and circulates around the posterior and posterior sides of the neck of the humeral surgery. After entering the deltoid space, it is divided into anterior and posterior branches.

Branch:

Anterior branch, hair branch on the deep side of the deltoid muscle, dominates the front of the deltoid muscle; cutaneous branch, distributed on the skin of the lower part of the deltoid muscle.

The posterior branch, the hair branch dominates the small round muscle and the back of the deltoid muscle; the dermal branch, which penetrates the deep fascia from the lower part of the posterior edge of the deltoid muscle, is called the lateral epithelial nerve of the arm, and is distributed in the lower part of the deltoid muscle and the triceps brachii Long head area of skin. When the axillary nerve is injured, the deltoid muscles atrophy, the arm cannot be lifted out (stretch), and the skin on the outer side of the arm is impaired.

The axillary nerve branches can be divided into four types according to their morphology. Type : the anterior branch, the small round muscle branch and the posterior branch are common in the axillary nerve trunk, this type has the largest proportion; type : the posterior deltoid muscle branch, small round muscle branch, and lateral epithelial nerves of the arm are all It occurs in the posterior branch of the axillary nerve; type III: the posterior deltoid muscle branch, the small round muscle branch, and the lateral epithelial nerve of the arm are common in the axillary nerve trunk; type IV: the small circular muscle branch is in the axillary nerve trunk.