Long Thoracic Nerve

Description

Originating from the ventral rami of C5 to C7, the long thoracic nerve descends along the lateral thoracic wall on the superficial surface of the serratus anterior, tracking inferiorly over successive ribs toward the midaxillary line. Posteriorly, the thoracic vertebrae and rib heads frame the nerve’s root contribution near the neck and upper trunk, while the scapulae lie posterolateral to the rib cage as mobile landmarks overlying the serratus anterior slips. Costal cartilages and the anterior rib cage complete the bony corridor as the nerve courses inferiorly, remaining relatively exposed compared with deeper elements of the brachial plexus. Anatomists and surgeons care about this nerve because its long, superficial path makes it a common casualty of axillary procedures and trauma. Injury produces serratus anterior palsy with medial scapular winging and impaired upward rotation, classically limiting shoulder abduction above the horizontal and destabilizing the scapulothoracic articulation. This view clarifies why iatrogenic injury can follow axillary lymph node dissection, chest tube placement near the midaxillary line, or traction during shoulder girdle surgery. A small structure, big functional penalty. Use this asset for brachial plexus and thoracic wall teaching in gross anatomy and physical diagnosis courses, and for figures in surgical texts discussing axillary dissection planes, mastectomy, or management of scapular winging. It also supports clinical education on distinguishing long thoracic nerve palsy from spinal accessory nerve injury and dorsal scapular nerve lesions during shoulder and scapular examination. Anatomical accuracy verified by SciePro's Medical Advisory Board.