The , commonly referred to as the axilla or "armpit," is a four-sided pyramidal space located at the junction of the upper limb and the thorax. It serves as a vital gateway for neurovascular and lymphatic structures traveling between the neck/torso and the upper extremity. Anatomical Boundaries
: The narrowest part, formed by the intertubercular sulcus (bicipital groove) of the humerus. Core Contents axillary cavity
: Formed by the subscapularis , teres major , and latissimus dorsi muscles. The , commonly referred to as the axilla
Anatomy, Shoulder and Upper Limb, Axilla - StatPearls - NCBI Core Contents : Formed by the subscapularis ,
: Consists of the serratus anterior muscle and the first four or five ribs.
: Primarily composed of the pectoralis major and pectoralis minor muscles.
The axilla is defined by several muscular and skeletal landmarks that shift shape with shoulder movement:
