Princeps pollicis artery
The princeps pollicis artery (also known as the first palmar metacarpal artery) is a branch of the radial artery that supplies the thumb (1 digit). It arises from the radial artery just as it enters the palm and courses distally along the palmar aspect of 1st metacarpal. At the 1metacarpophalangeal joint it bifurcates into two digital branches, radial and ulnar digital branches, that continue along the radial and ulnar aspects of the phalanges of the thumb respectively.
Variant anatomy
The radialis indicis artery may arise directly from the princeps pollicis artery rather than the deep palmar arch.