2 – Anatomy: The medial and lateral pectoral nerves

The lateral pectoral nerve typically origins from the spinal nerve roots C5-C7 and branches off the lateral cord of the brachial plexus

It runs across the superior-medial margin of the minor pectoral muscle piercing the clavipectoral fascia (see next page) and enters the fascial space between the minor and major pectoral muscles; it innervates the two pectoral muscles

The medial pectoral nerve origins from C8-T1 and branches off the medial cord of the brachial plexus

It typically pierces the minor pectoral muscle and enters the fascial space between the minor and major pectoral muscles; it innervates the two pectoral muscles

The two pectoral nerves run adjacent to the pectoral branch of the thoracoacromial artery in the fascial space between the minor and major pectoral muscles