The superficial palmar arch is sometimes referred to as the superficial volar arch or the arcus pamaris superficialis. It is also sometimes called the superficial ulnar arch or the arcus volaris superficialis. It is formed by the ulnar artery and the palmar branch of the radial artery. In some people, the radial artery does not contribute to the formation of the palmar arch. In these minority of cases, the anastomoses, the princeps pollicis artery, the median artery, and radialis indicis arteries comprise this arch. Beside the superficial arch lies the superficial palmar artery, also called the superficial palmar branch. It supplies blood to each of the lumbrical muscles. The superficial and deep palmar arches serve as a network of arteries inside the palm. Three of these arteries in the palmar network extend down the lumbrical muscles. Located across the face of the palm, the superficial palmar arch curves downward across the hand. When the thumb is fully extended, it lies at the same level as the thumb. The superficial palmar arch lies further away from the thumb than the deep palmar arch.