The Posterior Carpal Branch comes off about an inch and a half above the pisiform bone: it winds round the inferior extremity of the ulna to the back of the carpus, in passing beneath the tendon of the flexor ulnaris muscle: it sends small branches to the little finger, and terminates by anastomosing with the posterior carpal branch of the radial.

After the ulnar artery has arrived in the palm of the hand, it terminates by dividing into the communicans profunda and palmaris superficialis branches.