Structures of the axilla

Structures of the axilla. Most of the anterior wall of the axilla and the axillary fat pad have been removed, revealing the axilla's medial and posterior walls and neurovascular contents. Of the structures forming the anterior wall, only portions of the pectoralis major (attaching ends, a central part overlying the pectoralis minor, and a cube of muscle reflected superior to the clavicle) and the pectoralis minor remain. All the clavipectoral fascia has been removed, as has the axillary sheath surrounding the neurovascular bundle. Observe the axillary artery emerging from the cervicoaxillary canal inferior to the clavicle and subclavius muscle and then passing a finger's breadth inferior to the coracoid process of the scapula. As the axillary artery passes through the axilla, it is surrounded by the brachial plexus of nerves. The major nerves arising from the lateral and medial cords (anterior divisions) of the plexus have been elevated by an applicator stick.