Thoracodorsal n.

The thoracodorsal nerve, also known as the middle subscapular nerve or the long subscapular nerve, supplies the latissimus dorsi muscle.

It arises from the brachial plexus. It derives its fibers from the sixth, seventh, and eighth cervical nerves. It is derived from their ventral rami, in spite of the fact that the latissimus dorsi is found in the back. The thoracodorsal nerve is a branch of the posterior cord of the brachial plexus, and is made up of fibres from the posterior divisions of all three trunks of the brachial plexus.

It follows the course of the subscapular artery, along the posterior wall of the axilla to the Latissimus dorsi, in which it may be traced as far as the lower border of the muscle. It supplies latissimus dorsi on its deep surface.