Anterior Ramus of Sixth Cervical Nerve

Origin

The anterior ramus of the sixth cervical nerve originates from the sixth cervical nerve.

Course

The anterior ramus of the sixth cervical nerve originates in the neck, lateral to the intervertebral foramen between the fifth and sixth cervical vertebrae. It runs laterally towards the space between the anterior and middle scalene muscles where it joins the anterior ramus of the fifth cervical nerve to form the superior trunk of the brachial plexus.

Branches

The anterior ramus of the sixth cervical nerve is the sixth cervical root of the brachial plexus. It gives rise to the following nerves (with contributions from other roots in parentheses):

—subclavian nerve (C5);

—long thoracic nerve (C5, C7).

Together with the anterior ramus of the fifth cervical nerve, it gives rise to the superior trunk of the brachial plexus.

Supplied Structures

The anterior ramus of the sixth cervical nerve carries both sensory and motor innervation. Broken down by nerve, the structures supplied directly by the nerves of the anterior ramus of the sixth cervical nerve are:

—subclavian nerve supplies motor innervation of the subclavius muscle;

—long thoracic nerve supplies motor innervation of the serratus anterior muscle.

The anterior ramus of the sixth cervical nerve also gives rise to the superior trunk of the brachial plexus and carries fibers from all nerves associated with the superior trunk. Broken down by nerve, the structures innervated by the sixth cervical ramus via the superior trunk are as follows.

—Lateral pectoral nerve supplies motor innervation of the pectoralis major muscles and, through the ansa pectoralis, a minor contribution to the pectoralis minor muscle.

—Musculocutaneous nerve supplies sensory to skin of the lateral forearm and motor innervation to the muscles of the anterior compartment of the arm.

—Median nerve supplies sensory to skin of the lateral palmar surface of the hand and finger tips and all intrinsic muscles of the hand and forearm flexors not innervated by the ulnar nerve.

—Upper subscapular nerve supplies motor innervation of the subscapularis muscle.

—Thoracodorsal nerve supplies motor innervation of the latissimus dorsi muscle.

—Lower subscapular nerve supplies motor innervation of the subscapularis muscle.

—Axillary nerve supplies sensory to skin of the lateral arm and motor innervation of the deltoid and teres minor muscles.

—Radial nerve supplies sensory to skin of the posterolateral arm, posterior forearm, and posterolateral hand and motor innervation to the muscles of the posterior compartment of the arm and forearm.