Superficial palmar arch
The superficial palmar arch is formed predominantly by the ulnar artery, with a contribution from the superficial palmar branch of the radial artery.[3] The arch passes across the palm in a curve (Boeckel's line) with its convexity downward, With the thumb fully extended, the superficial palmar arch would lie approximately 1 cm from a line drawn between the first web space to the hook of hamate (Kaplan's cardinal line).Three common palmar digital arteries arise from the arch, proceeding down on the second, third, and fourth lumbrical muscles, respectively.Four digital branches arise from this palmar arch that supplies the medial/ulnar 3 1/2 fingers.This article incorporates text in the public domain from page 598 of the 20th edition of Gray's Anatomy (1918)