The brachiocephalic vein is a major blood vessel in the human body that plays a crucial role in returning deoxygenated blood to the heart. It is formed by the union of the subclavian vein and the internal jugular vein on each side of the body. There are two brachiocephalic veins: the right and the left, which drain blood from the upper limbs and head. These veins converge to form the superior vena cava, which empties into the right atrium of the heart. The brachiocephalic veins are important for maintaining proper blood circulation and are often involved in medical procedures, such as central venous catheterization.