Ulnar Artery

The ulnar artery is a branch of the brachial artery.
In Section 8 the ulnar artery splits into two main branches – the superficial palmar arch and the deep palmar arch.
In the hand and wrist, the ulnar artery is located in Guyon’s canal.
In Guyon’s canal the ulnar artery is superficial to the ulnar nerve.

Diagrams & Photos

Diagram showing the ulnar artery, superficial vascular arch and deep vascular arch.
Ulnar artery in Guyon's canal dorsal to ulnar nerve. Yellow arrow at cut edge of pisohamate ligament and transverse carpal ligament.
Ulnar artery exiting Guyon's canal at junction of palmar sections 7 and 8.

Key Points

There is significant variation in the completeness of the superficial palmar arch and the contributions by the ulnar and/or radial artery.
The superficial palmar arch anastomosis with the superficial branch of the radial artery at the border between the thenar space and the mid-palmar compartment space.
The deep palmar branch of the ulnar artery follows the motor branch of the ulnar nerve around the hook of the hamate, under the hypothenar muscles originating from the hook and then radially onto the floor of the carpal tunnel and enters the adductor hiatus between heads of the adductor pollicis where it is covered by adipose tissue.
The ulnar artery has three layers - the intima composed of endothelial cells, the media composed of smooth muscle cells and elastin, and the outer adventitia composed of fibrous tissues.