Long Thoracic Nerve, Gross Anatomy

Description

Arising from the anterior rami of C5, C6, and C7, the long thoracic nerve descends in the posterior triangle of the neck, then courses inferiorly along the lateral thoracic wall on the superficial surface of serratus anterior. Proximally, it lies posterior to the clavicle and near the brachial plexus roots, with the sternocleidomastoid and trapezius forming key muscular borders in the cervical region. Distally, the nerve tracks medial to the shoulder contour and over the upper ribs, where serratus anterior digitations interdigitate with the external intercostals. Bony landmarks such as the clavicle, scapula, and superior ribs anchor the relationships. This course matters because the long thoracic nerve is long, superficial, and exposed where clinicians work. Injury during axillary lymph node dissection, mastectomy, first rib procedures, or even chest tube placement can denervate serratus anterior, producing medial scapular winging that becomes more obvious with forward flexion or a wall push-up. Traction in overhead athletics and blunt trauma to the lateral chest also target the nerve along the midaxillary line. Small nerve, big functional cost. Use this artwork when teaching brachial plexus derivatives and thoracic wall innervation in gross anatomy, physical therapy, or surgical anatomy modules focused on scapulothoracic mechanics. It also fits operative atlases and patient-facing education on postoperative winged scapula after breast or axillary surgery. Anatomical accuracy verified by SciePro's Medical Advisory Board.