Anatomy, Head and Neck, Posterior Humeral Circumflex Artery

The posterior humeral circumflex artery (PHCA) originates from the third part of the axillary artery immediately posterior to the origin of the anterior humeral circumflex artery (AHCA). The PHCA and other neurovascular structures leave the axilla by passing through the quadrangular space between the teres major and minor muscles, the long head of the triceps brachii muscle, and the surgical neck of the humerus. After the PHCA passes through the quadrangular space, it curves around the surgical neck of the humerus and supplies the surrounding muscles and the shoulder joint. It also forms rich anastomoses with the AHCA and branches from the profunda brachii, suprascapular, and thoracoacromial arteries.