What vessel does the blood from the axillary vein drain into?

The blood from the axillary vein drains into the subclavian vein. The axillary vein is formed by the confluence of the brachial and basilic veins and runs along the axillary artery. Once the axillary vein reaches the outer border of the first rib, it becomes the subclavian vein.

The subclavian vein then eventually contributes to the formation of the brachiocephalic vein on each side. The brachiocephalic veins from both sides merge to form the superior vena cava, which returns deoxygenated blood to the heart. The innominate vein is another term for the brachiocephalic vein, but the term is less commonly used in modern anatomy. Thus, it's more accurate to state that the axillary vein directly drains into the subclavian vein rather than the innominate (brachiocephalic) vein.