The brachial vein is a major blood vessel located in the upper arm. It is formed by the merging of the radial and ulnar veins, which drain blood from the forearm. The brachial vein runs alongside the brachial artery, carrying deoxygenated blood back to the heart. This vein plays a crucial role in the circulatory system, helping to maintain proper blood flow. It typically travels through the arm's anterior compartment and is often used in medical procedures, such as blood draws or intravenous access, due to its accessibility and size.