The axilla (or armpit, underarm, or oxter) is the area on the human body directly under the joint where the arm connects to the shoulder. It also provides the under-arm sweat gland.
Anatomically, the boundaries of the axilla are:
- superiorly: by the outer border of first rib, superior border of scapula, and posterior border of clavicle
- medially: serratus anterior and by the ribcage
- anteriorly: by the pectoralis major, minor, and subclavius
- posteriorly: by the subscapularis above, and teres major and latissimus dorsi below
- laterally: by the intertubercular sulcus (coracobrachialis and the short head of the biceps brachii are in the axilla.