The deep brachial artery (or deep artery of arm) is also known as the profunda artery. It is the primary blood vessel in the upper arm. This artery supplies blood to the muscles of the upper arm and to the shaft of the humerus. Once it branches, it also supplies blood to the elbow joint, the forearm, and the hand. The deep brachial artery is deep within the arm, and runs parallel to the humerus. It originates just below the shoulder at the axillary artery, and branches into two smaller arteries, the radial and ulnar arteries, at the elbow.