Corpus: Ulnar artery
Definition
The ulnar artery is an artery located in the forearm. It arises just below the elbow joint along with the radial artery from the brachial artery.
Course
The ulnar artery courses below the pronator teres muscle and the flexor digitorum superficialis muscle ulnarly and distally. It then runs in the ulnar antebrachial groove, at or below the lateral edge of the flexor carpi ulnaris muscle, and on the flexor digitorum profundus muscle towards the wrist.
Together with the ulnar nerve, the ulnar artery passes radially through Guyon's canal, lateral to the pisiform bone, to the palm of the hand. It forms the superficial palmar arch on the tendons of the finger flexors, from which arteries branch off to supply the fingers.
In its course to the palm of the hand, the ulnar artery is protected by the palmar aponeurosis and the palmaris brevis muscle.
Branches
The ulnar artery gives off the following branches:
- Ulnar recurrent artery
- Common interosseous artery
- Posterior interosseous artery
- Anterior interosseous artery
- Palmar carpal branch (to the palmar carpal network)
- Dorsal carpal branch (to the dorsal carpal network)
- Deep palmar branch
The terminal branch of the ulnar artery bends towards the thumb and, along with the superficial palmar branch of the radial artery, forms the superficial palmar arch.
Clinic
The ulnar artery can be affected in severe forearm fractures.
The Allen's test, involving alternating compression of the radial and ulnar arteries, can be used to assess collateral circulation between the territories of both arteries.