Quick Facts
Origin: Medial cord of the brachial plexus.
Course: It runs anteriorly into the pectoralis minor muscle and then the pectoralis major muscle.
Branches: No named branches.
Supply: Motor innervation. It supplies both the pectoralis minor and pectoralis major muscles.
Related parts of the anatomy
Origin
The medial pectoral nerve arises from the medial cord of the brachial plexus. It contains fibers from spinal cord segments C8 and T1.
The medial pectoral nerve also carries axons from spinal cord segments C5, C6, and C7 via a communicating branch from the lateral pectoral nerve.
Course
The medial pectoral nerve emerges from the medial cord medial to the second portion of the axillary artery. Typically, its origin is proximal to the origin of both the medial brachial cutaneous and medial antebrachial cutaneous nerves.
It runs anteriorly between the axillary artery and vein, penetrating the overlying pectoralis minor muscle. The medial pectoral nerve then emerges anteriorly to pierce the pectoralis major muscle.
Branches
Along its course, the medial pectoral nerve does not branch. Commonly, it does receive a communicating branch from the lateral pectoral nerve shortly distal to its origin.
Supplied Structures
The medial pectoral nerve is a motor nerve. It supplies the pectoralis minor muscle and the sternocostal head of the pectoralis major muscle.
