The anterior wall of the axilla consists of the major and minor pectoral muscles and the clavipectoral fascia
The medial wall of the axilla is the lateral thoracic wall with costae I-IV and intercostal muscles – and the serratus anterior muscle
The lateral wall is the intertubercular groove of the humerus and the posterior wall is the subscapularis, teres major and latissimus dorsi muscles.
The axilla contains some nerves that are relevant for axillary extension of breast surgery:
1) the lateral cutaneous branches of the intercostal nerves 2) the anterior intercostal branches of the intercostal nerves 3) the long thoracic nerve that innervates the serratus anterior muscle 4) the thoracodorsal nerve that innervates the latissimus dorsi muscle
Lateral cutaneous branch of intercostal nerves I (black arrow), II (white arrow), IV (green arrow), major and minor pectoral muscles (green and cyan asterixs), latissimus dorsi (magenta asterix), serratus anterior (blue asterix), long thoracic nerve (magenta arrows), thoracodorsal nerve (cyan arrows)
