Anatomy of the Volar Branch of the Ulnar Nerve at the Wrist

Approximately 5 cm proximal to the wrist, the ulnar nerve divides into its terminal branches: The dorsal and volar branches.

The volar branch crosses the flexor retinaculum on the lateral side of the pisiform and terminates into superficial and a deep branches.

The superficial branch supplies the palmaris brevis and the skin on the ulnar side of the hand.

The deep branch passes between the abductor digiti minimi and flexor digiti minimi brevis muscles, perforates the opponens digiti minimi, and travels deep to the flexor tendons.

The sequence of axial MRIs above shows the terminal branches of the ulnar nerve in the hand and wrist.

References

Gray's anatomy.