Anatomical Structure and Location of the Medial Pectoral Nerve

Description

Anterior chest wall anatomy is rendered in a male upper torso, with the medial pectoral nerve traced from the brachial plexus into the pectoral region. From its origin off the medial cord, the nerve runs inferior and anterior toward pectoralis minor, commonly piercing that muscle before distributing to the deep surface of pectoralis major (sternocostal head), lying medial to the humerus and deep to the clavicular head of pectoralis major. Surrounding landmarks include the clavicle superiorly, the ribs and costal cartilages deep to the pectoral muscles, and the scapula lateral and posterior to the chest wall. Color separation keeps the neurovascular logic readable. Understanding this course matters because the medial pectoral nerve is encountered when working in the axilla and during breast and pectoral surgery where the pectoral fascia and pectoralis minor are manipulated. Injury can denervate portions of pectoralis major and minor, producing weakness in adduction and internal rotation, and it can contribute to postoperative anterior chest wall pain or altered shoulder mechanics. It also clarifies a common teaching point: despite its name, the medial pectoral nerve often supplies pectoralis major, and it typically communicates with the lateral pectoral nerve in the pectoral loop anterior to the axillary artery. Use this figure in gross anatomy labs, peripheral nerve teaching blocks, and surgical education materials covering axillary dissection, mastectomy approaches, and pectoral region flaps, where correct identification of the medial cord branches reduces iatrogenic denervation. A clean option for atlases and journal figures that need the pectoralis major and minor layers read alongside the brachial plexus. Anatomical accuracy verified by SciePro's Medical Advisory Board.