Radial artery
Arteria radialis
The radial artery is the smaller, lateral terminal branch of the brachial artery. It runs down the lateral side of the forearm to the wrist, where the radial pulse is felt, then crosses the anatomical snuffbox and forms the deep palmar arch.
Overview
Forearm. The radial artery begins in the cubital fossa. In the upper forearm it lies under brachioradialis, on supinator, pronator teres, flexor digitorum superficialis and flexor pollicis longus. The superficial branch of the radial nerve lies lateral to it. Above the wrist it lies on the distal radius, covered only by skin and fascia, between the tendons of brachioradialis and flexor carpi radialis. This is where the radial pulse is felt.
Wrist and hand. The artery then winds around to the back of the wrist across the floor of the anatomical snuffbox, over the scaphoid and trapezium and deep to the abductor pollicis longus, extensor pollicis brevis and extensor pollicis longus tendons. It enters the palm between the two heads of the first dorsal interosseous muscle and joins the deep branch of the ulnar artery to form the deep palmar arch.
Anatomy
- Branches
The radial recurrent artery, muscular branches, palmar and dorsal carpal branches, the superficial palmar branch (which helps complete the superficial palmar arch), the princeps pollicis artery, the radialis indicis artery and the deep palmar arch.
Function
- Supplies the lateral forearm muscles, the wrist and the thumb and index finger.
- Forms the deep palmar arch.
Clinical significance
Arterial access
The radial artery is the standard site for arterial blood gas sampling and arterial lines. It is now the preferred access route for coronary angiography and PCI, because bleeding complications are fewer than with femoral access.
Allen's test
Before cannulating or harvesting the radial artery, Allen's test checks that the ulnar artery and palmar arches can supply the hand alone. Both arteries are compressed while the patient makes a fist, the ulnar artery is released, and colour should return to the hand within about 5–10 seconds.
Haemodialysis fistula
A radiocephalic (Brescia–Cimino) arteriovenous fistula at the wrist joins the radial artery to the cephalic vein. It is the preferred first access for long-term haemodialysis.
Compiled from standard anatomy and physiology references — see the Cardiovascular System sources. For education only; not medical advice.