Nerves of Upper Limb (Left)

Description

The nerves of the upper limb arise from the brachial plexus. The brachial plexus is composed of anterior (ventral) rami from spinal nerves C5, C6, C7, C8, and T1. These rami mix and send nerves to their respective targets.

The brachial plexus is organized into five parts:

—roots;

—trunks;

—divisions;

—cords;

—branches.

Nerves emerging from the roots of the brachial plexus (anterior rami) include the dorsal scapular, subclavian, and long thoracic nerves. These are motor nerves that innervate muscles in the shoulder region.

The only nerve that typically emerges from the trunks of the brachial plexus is the suprascapular nerve. This innervates the supraspinatus and infraspinatus muscles of the scapula.

Typically no nerves emerge from the divisions of the brachial plexus This portion of the brachial plexus serves to reorganize the plexus into anterior and posterior components that largely correspond to the anterior and posterior compartments of the arm and forearm.

Several branches arise from the cords of the brachial plexus.

—The lateral cord of the brachial plexus gives rise to the lateral pectoral nerve.

—The posterior cord of the brachial plexus gives rise to the superior subscapular, thoracodorsal, and inferior subscapular nerves.

—The medial cord of the brachial plexus gives rise to the medial cutaneous nerve of the arm, medial cutaneous nerve of the forearm, and medial pectoral nerve.

The terminal branches of the cords of the brachial plexus are the ulnar, radial, musculocutaneous, axillary, and median nerves.