The axillary vein is a major blood vessel located in the upper arm and shoulder area. It is formed by the convergence of the brachial veins, which drain blood from the arm, and the cephalic vein, which collects blood from the outer side of the arm. The axillary vein runs alongside the axillary artery and plays a crucial role in returning deoxygenated blood to the heart. As it travels upward, the axillary vein eventually becomes the subclavian vein as it passes the first rib. This transition is important for the proper circulation of blood throughout the upper body. The axillary vein is also significant in medical procedures, such as central venous catheter placement.