Long Thoracic Nerve, Lateral View

Description

Arising from the anterior rami of C5 to C7 at the lateral cervical region, the long thoracic nerve courses inferiorly along the superficial (external) surface of serratus anterior, just deep to the axillary fascia and anterior to the ribs. In lateral profile, its proximal relationship to the scalene muscles is apparent as it descends posterior to the clavicle toward the thoracic wall, with the brachial plexus roots and trunks nearby in the posterior triangle. Superficial landmarks often include sternocleidomastoid anteriorly and trapezius posteriorly, with the cervical vertebrae forming the deep bony backdrop. A long, exposed path. That length matters clinically because the long thoracic nerve is vulnerable where it runs on the chest wall and in the axilla, and injury denervates serratus anterior, producing medial scapular winging and impaired overhead elevation. Surgeons and trainees look for this nerve during axillary lymph node dissection and mastectomy, and anesthetists consider it when placing regional blocks near the brachial plexus to avoid iatrogenic neuropraxia. This lateral orientation also supports teaching the distinction between scapular winging from long thoracic nerve palsy versus spinal accessory nerve injury affecting trapezius. Useful in gross anatomy and neuroanatomy courses when introducing brachial plexus branches, and in operative anatomy texts covering breast, axillary, and thoracic wall approaches where serratus anterior must be respected. It also fits clinical skills modules that correlate physical exam findings of winged scapula with specific peripheral nerve lesions. Anatomical accuracy verified by SciePro's Medical Advisory Board.