Medial Pectoral Nerve - Podcast Version 0:00 / 0:00 1x 0.25x 0.5x 0.75x 1x 1.25x 1.5x 1.75x 2x The medial pectoral nerve is a motor nerve arising from the medial cord of the brachial plexus. It supplies motor innervation to the pectoralis minor and the sternocostal head of pectoralis major. Pro Feature - 3D Model You've Discovered a Pro Feature Access our 3D Model Library Explore, cut, dissect, annotate and manipulate our 3D models to visualise anatomy in a dynamic, interactive way. Learn More Course The medial pectoral nerve originates from the medial cord of the brachial plexus, containing fibres from C8 and T1. It arises posterior to the first part of the axillary artery, before passing medially to the second part of the artery. It then runs anteriorly between the axillary artery and vein, where it commonly recieves a branch of the lateral pectoral nerve to form a nerve loop (ansa pectoralis). From here, it penetrates the pectoralis minor muscle, providing motor innervation. Some fibres continue through the muscle to supply the lower portion of the sternocostal head of the pectoralis major. By TeachMeSeries Ltd (2026) Fig 1Medial and lateral pectoral nerves. Pro Feature - Dissection Atlas You've Discovered a Pro Feature Access our Dissection Image Library Enhance your understanding with high-resolution dissection images showcasing real-life anatomy. Learn More Motor Functions The medial pectoral nerve suppies motor innervation to both: Pectoralis minor Pectoralis major (sternocostal head) By TeachMeSeries Ltd (2026) Fig 2The sternal and clavicular heads of the pectoralis major. By TeachMeSeries Ltd (2026) Fig 3The serratus anterior and pectoralis minor muscles. Frequent questions What is the medial pectoral nerve? The medial pectoral nerve is a motor nerve that originates from the medial cord of the brachial plexus, specifically involving fibres from C8 and T1. It is responsible for innervating the pectoralis minor and the sternocostal head of the pectoralis major muscles. What muscles are innervated by the medial pectoral nerve? The medial pectoral nerve innervates the pectoralis minor and the sternocostal head of the pectoralis major. This motor innervation is crucial for shoulder movement and stability. Where does the medial pectoral nerve originate? The medial pectoral nerve arises from the medial cord of the brachial plexus, positioned posterior to the first part of the axillary artery. It then courses medially and anteriorly, running between the axillary artery and vein. What is the course of the medial pectoral nerve? The medial pectoral nerve travels from the medial cord of the brachial plexus, passing posterior to the axillary artery and then anteriorly between the axillary artery and vein. It typically receives a branch from the lateral pectoral nerve, forming a nerve loop before penetrating the pectoralis minor muscle. What is the clinical significance of the medial pectoral nerve? The medial pectoral nerve is clinically significant due to its role in innervating key muscles involved in shoulder function. Damage to this nerve can lead to weakness in shoulder movements and impaired stability, highlighting its importance in upper limb mechanics. Rate This Article