: Formed by the subscapularis , teres major , and latissimus dorsi muscles.
: Consists of the serratus anterior muscle and the first four or five ribs.
: Formed by the axillary fascia and the skin of the armpit. axillary cavity
: The narrowest part, formed by the intertubercular sulcus (bicipital groove) of the humerus. Core Contents
: The top of the pyramid, formed by the first rib , the scapula , and the clavicle . It connects the axilla to the posterior triangle of the neck. : Formed by the subscapularis , teres major
The cavity is filled with fat and connective tissue, which cushions several major structures:
: Primarily composed of the pectoralis major and pectoralis minor muscles. : Formed by the subscapularis
Anatomy, Shoulder and Upper Limb, Axilla - StatPearls - NCBI