Ulnar canal
The ulnar canal or ulnar tunnel (also known as Guyon's canal or tunnel) is a semi-rigid longitudinal canal in the wrist that allows passage of the ulnar artery and ulnar nerve into the hand. (These are named after the ulna, the long bone on the little finger side of the arm.) The roof of the canal is made up of the superficial palmar carpal ligament, while the deeper flexor retinaculum and hypothenar muscles comprise the floor.