Brachial plexus Brachial plexus The brachial plexus is a network of nerves formed by the ventral rami of the lower four cervical nerves and first thoracic nerve (C5, C6, C7, C8, and T1). This plexus extends from the spinal cord, through the cervicoaxillary canal in the neck, over the first rib, and into the armpit. It supplies afferent and efferent nerve fibers to the chest, shoulder, arm and hand. The brachial plexus is divided into five "roots", three "trunks", six "divisions" (three anterior and three posterior), three "cords", and five "branches". There are five "terminal" branches and numerous other "pre-terminal" or "collateral"
Suprascapular artery Suprascapular artery The suprascapular artery is a branch of the thyrocervical trunk. At first, it passes downward and laterally across the scalenus anterior and phrenic nerve, being covered by the sternocleidomastoid muscle; it then crosses the subclavian artery and the brachial plexus, running behind and parallel with the clavicle and subclavius muscle and beneath the inferior belly of the omohyoid to the superior border of the scapula. It passes over the superior transverse scapular ligament (unlike the suprascapular nerve, which passes below the ligament). The artery then enters the supraspinatous fossa of the scapula. It travels close to the bone,