|Artery: Princeps pollicis artery
|Palm of left hand, showing position of skin creases and bones, and surface markings for the volar arches.
||arteria princeps pollicis
||subject #151 595
The princeps pollicis (principal artery of the thumb) arises from the radial artery just as it turns medially towards the deep part of the hand; it descends between the first dorsal interosseous muscle and the oblique head of the adductor pollicis, along the medial side of the first metacarpal bone to the base of the proximal phalanx, where it lies beneath the tendon of the flexor pollicis longus muscle and divides into two branches.
These make their appearance between the medial and lateral insertions of the adductor pollicis, and run along the sides of the thumb, forming an arch on the palmar surface of the distal phalanx, from which branches are distributed to the integument and subcutaneous tissue of the thumb.
Additional images 
The radial and ulnar arteries. (Arteria princeps pollicis visible at lower left.)
Ulnar and radial arteries. Deep view.
External links 
This article incorporates text from a public domain edition of Gray's Anatomy.