Glossopharyngeal Nerve, Gross Anatomy

Description

Arising from the anterior rami of C5 to T1, the right brachial plexus is shown emerging in the posterior triangle of the neck between the anterior and middle scalene muscles, then passing inferiorly and laterally toward the clavicle and first rib. Roots converge into superior, middle, and inferior trunks, each dividing into anterior and posterior divisions that reorganize around the axillary artery as lateral, posterior, and medial cords. Distal branches track into the axilla and proximal arm, where the musculocutaneous, median, ulnar, radial, and axillary nerves take recognizable courses relative to the pectoralis minor, coracoid process, and surgical neck of the humerus. Small. Blue vessels accompany the cords and terminal branches in the axillary sheath. Course relationships in this region matter because traction and compression injuries cluster where the plexus is tethered, at the interscalene interval, over the first rib, and beneath the pectoralis minor during hyperabduction. Erb palsy patterns reflect upper trunk involvement (C5 to C6) with weakness in deltoid and biceps, while Klumpke-type deficits track to the lower trunk and medial cord, often affecting intrinsic hand function and sometimes the sympathetic chain. For regional anesthesia, this anatomy underpins interscalene and supraclavicular brachial plexus blocks, and it clarifies why phrenic nerve paresis or pneumothorax can complicate certain approaches. Ideal for gross anatomy labs, neuroanatomy teaching slides, and orthopedic or peripheral nerve surgery texts that need clear cord and terminal branch relationships to the shoulder musculature and axillary vessels. It also fits clinical education materials on thoracic outlet syndrome, axillary dissection landmarks, and brachial plexus injury mechanisms. Anatomical accuracy verified by SciePro's Medical Advisory Board.