Possible anastomoses between the long branches of the brachial plexus and their clinical significance.

The brachial plexus consists of nerves that supply the upper limb and some nerves of the back, torso, and neck. It is formed by the ventral rami of C5 to T1 (in some cases, C4 or T2 also contribute). The anterior rami of the spinal nerves unite to the roots, trunks, divisions, cords, and terminal branches that innervate muscles and skin.