Which of the following is NOT a deep vein of the upper extremity?

The cephalic vein is not classified as a deep vein of the upper extremity; instead, it is considered a superficial vein. Superficial veins are those that are located closer to the surface of the skin and are generally more visible, whereas deep veins are situated deeper within the tissues and accompanying arteries. The cephalic vein runs along the outer side of the forearm and arm and is often used for venous access due to its accessibility.

In contrast, the subclavian vein, brachial vein, and axillary vein are all classified as deep veins. The subclavian vein is located beneath the clavicle and is critical for draining blood from the upper extremity to the heart. The brachial vein accompanies the brachial artery and plays an essential role in draining blood from the arm. The axillary vein is formed by the convergence of the brachial and basilic veins and is situated deep in the axilla (armpit area). These deep veins are essential for proper venous return and have significant anatomic and physiological roles in the upper extremity's vascular system.