Muscular Branch of Radial Nerve to Long Head of Triceps Brachii (Left)

Origin

A motor nerve branch to the long 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. While passing through the space (before entering the spiral groove), the radial nerve provides muscular innervation to the long head of triceps brachii muscle.

Branches

There are no named branches.

Supplied Structures

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