The axilla is the region between the arm and the thorax. It contains a number of important structures running to the arm and is also one of the main areas for drainage of lymph from the breast. 'Armpit' or 'underarm' refer to the inferior skin (floor) of the axilla, or the hollow formed by that skin (the axillary fossa).
|Arterial supply:||Axillary artery|
|Venous drainage:||Axillary vein|
|Lymphatic drainage:||Axillary lymph nodes|
|Vertebral levels:||Extends to level of 4th rib|
|Search for Axilla in Gray's.|
The axilla is a pyramidal space located inferior to the shoulder joint, at the junction of the upper limb and thorax. It provides a space through which many of the important vessels and nerves pass from the trunk to the upper limb. The space is almost obliterated in full abduction of the shoulder, a position in which the contents become vulnerable.
The anterior axillary fold is the inferior border of pectoralis major covered by fascia and skin.
The posterior axillary fold is formed by latissimus dorsi, teres major and skin.
The cervoaxillary canal:
An axillary sheath surrounds the vessels and nerves proximally, a continuation of the cervical fascia.