What artery is located in the quadrilateral space alongside the axillary nerve?

The posterior humeral circumflex artery is indeed located in the quadrilateral space, which is an anatomical area bordered by the teres minor and major muscles, the long head of the triceps brachii, and the humerus. It travels alongside the axillary nerve, making this combination key to understanding the neurovascular anatomy in this region.

This artery arises from the axillary artery and supplies blood to the shoulder and surrounding muscles, which is essential for maintaining the vascular supply during arm movements. The presence of both the posterior humeral circumflex artery and the axillary nerve in this space is clinically significant, particularly in injuries or shoulder surgeries, as they can both be affected.

The other choices do not travel through the quadrilateral space. The anterior humeral circumflex artery is typically positioned more anteriorly and does not share the same pathway. The subclavian artery is proximal and does not enter the quadrilateral space, while the deep brachial artery, which primarily supplies the posterior compartment of the arm, lies more distal and does not interact with the structures in the quadrilateral space. Understanding the relationships of these vessels and nerves is crucial for diagnosing and managing shoulder-related pathologies.