Overview
The ulnar artery is a terminal branch of the brachial artery, arising at the proximal aspect of the forearm. Along with the radial artery, it is one of the main arteries of the forearm.
Origin
The ulnar artery arises as a large terminal branch of the brachial artery at the inferior aspect of the cubital fossa
Course
- Begins superficial to brachialis and flexor digitorum profundus
- Then courses along the ulnar aspect of the forearm deep to the flexor digitorum superficialis, pronator teres and flexor carpi radialis muscles.
- Courses along the surface of the flexor carpi ulnaris for the majority of its course.
- It enters the hand with the ulnar nerve and vein by passing through the Guyon canal (ulnar canal) located between the pisiform and the hook of hamate.
- It then divides into its terminal branches at the carpal region of the hand
Termination
The ulnar artery terminates at the hand via its branches; the palmar carpal arch, the superficial palmar arch, and the dorsal carpal branch
Branches
- Anterior ulnar recurrent artery – ascends up the elbow, anterior to the medial epicondyle and anastomoses with the inferior ulnar collateral artery (branch of the brachial artery)
- Posterior ulnar recurrent artery – ascends up the elbow, posterior to the medial epicondyle and anastomoses with the superior ulnar collateral artery (branch of the brachial artery)
- Common interosseous artery – branches off the medial aspect of the ulnar artery, just distal to the anterior and posterior ulnar recurrent arteries. Divides into:
- Anterior interosseous artery – runs on the anterior surface of the interosseous membrane together with the anterior interosseous nerve (branch of the median nerve). It runs between flexor digitorum profundus (medially) and flexor pollicis longus (laterally), supply both. It supplies the deep extensor muscles within the posterior compartment of the arm via small branches which pierce the interosseous membrane. It also supplies nutrient vessels to the radius and ulna.
- Posterior interosseous artery – pierces the upper aspect of the interosseous membrane to enter the posterior compartment of the forearm. It gives off the recurrent interosseous artery. It then descends on the posterior aspect of the posterior interosseous membrane alongside the interosseous nerve (branch of the radial nerve), between the supinator and abductor pollicis longus, supplying both. It terminates by anastomoses with the anterior interoseous artery, forming the dorsal carpal arch.
- Recurrent interosseous artery – travels posteriorly through the interosseous membrane to anastomose with the middle collateral artery (branch of the brachial artery)
- Palmar carpal arch – a small vessel which crosses the front of the carpus beneath the tendons of the Flexor digitorum profundus, and anastomoses with the corresponding branch of the radial artery.
- Superficial palmar arch
- Dorsal carpal branch
Anatomical Variants
- Persistent median artery – arises from the common or anterior interosseous artery and accompanies median nerve through the carpal tunnel