The princeps pollicis artery branches from the radial artery near the wrist and extends into the hand toward the thumb. It is also known as the principal artery of the thumb. The radial artery is one of the two arteries used to supply blood to the forearm and hand. The other artery that performs this function is the ulnar artery. The princeps pollicis artery branches off into two smaller branches near the second joint of the thumb. It supplies blood to the all of the tissues of the thumb. Occasionally, an individual may experience an arterial blockage in the radial artery. This may cause blood to flow more slowly or not at all to the smaller arteries of the hand. In some cases, a complete blockage may occur. This can cause cell death to the areas that are not receiving oxygen. In such circumstances, if the princeps pollicis artery and other arteries of the hand are not able to supply the cells with oxygen, then emergent surgery may be required to correct or bypass the blockage.