Muscular Branch of Radial Nerve to Lateral Head of Triceps Brachii (Right)

Origin

Motor nerve branch to the lateral head of triceps brachii muscle originates from the radial nerve and contains motor nerve fibers from the C6—C8 cervical spinal segments.

Course

The radial nerve comes off from the posterior cord in the lower part of the axilla. Here it runs behind the third part of axillary artery while lying against the muscles of the posterior wall of the axilla, i.e., subscapularis, teres major, and latissimus dorsi muscles.

In the upper part of the arm, it descends posterolaterally (with the profunda brachii vessels) through the lower triangular space, between the shaft of the humerus, long head of triceps brachii, and teres major muscles. The nerve then enters the radial groove along with the profunda brachii vessels. It descends downwards and laterally between the lateral and medial heads of the triceps muscle, while in contact with the humerus. The radial nerve innervates the lateral head of the triceps brachii as it travels deep to the muscle.

Branches

There are no named branches.

Supplied Structures

The muscular branch of the radial nerve to lateral head of triceps provides motor innervation to the lateral head of triceps muscle. The radial nerve gives off several branches to innervate all three heads of the triceps brachii muscle.