Index
It is one of the two arteries in the forearm (the other is the ulnar artery).
According to the name, it is located on the lateral side along the radius of the bone. The radial artery is the smaller of the two terminal branches of the brachial artery.
Origin and termination of the radial artery
The radial artery originates as the brachial artery’s minor terminal branch in the elbow region at the level of the head of the radius bone. It is located on the lateral side of the forearm and participates in the deep palmar arch of the hand.
Radial artery course
It is executed inferolateral under the covering of the brachioradialis muscle.
It then lies lateral to the flexor carpi radialis tendon in the distal forearm and finally wraps around the lateral part of the radius and crosses the floor of the anatomical tobacco box to pass between the two heads of the first dorsal interosseous muscle and participate in the formation of the deep palmar arch.
Branches of the radial artery
The branches of the radial artery can be divided into three groups according to the region of the upper limb where they arise:
On the forearm
- Recurrent radial artery: Arises from the lateral side just below the origin of the radial artery and passes upward toward the anastomoses with the radial collateral branch of the deep brachial artery. Helps in the formation of anastomosis near the elbow joint.
- Palmar carpal branch: arises near the lower border of the pronator quadratus muscle. It runs through the wrist and terminates by anastomosis with the palmar branch of the ulnar artery.
- Superficial palmar branch: arises from the medial side of the radial artery just as it wraps around the lateral side of the wrist. It ends by anastomosis with the terminal portion of the ulnar artery, thus completing the superficial palmar arch of the hand.
On the wrist
- Dorsal carpal branch: a small vessel that arises from the radial artery and anastomoses with the corresponding component from the ulnar artery to form the dorsal arch of the carpal hand.
- First dorsal metacarpal artery: arises just before the radial artery passes between the two heads of the first dorsal interosseous muscle. It divides into two branches to supply the adjacent sides of the thumb and forefinger.
In the hand
- Princeps pollicis artery: It is also known as the main artery of the thumb. It arises from the radial artery just at the point where it turns to the medial side of the hand. The lateral part of the thumb is supplied.
- radial index artery: it is the radial artery of the index finger. It arises near the origin of the princeps pollicis artery and runs between the heads of the first dorsal interosseous muscle heads to reach the index finger’s lateral side. Supplies blood to the index finger.
- Deep palmar arch: exists as an arterial network found in the palm, formed by the terminal part of the radial artery and the deep palmar branch of the ulnar artery.
Radial artery in the hand
The radial artery leaves the lower end of the radius and slopes through the snuffbox onto the trapezius, thus passing the hand between the two heads of the first dorsal interosseous muscle. Lying now between this muscle and the adductor muscle emits two large branches.
The radial artery indices pass distally between the two muscles to emerge on the radial side of the index finger, which it supplies.
The Princeps pollicis artery passes distally along the metacarpal bone of the thumb and divides into its two palmar digital branches at the metacarpal head.
The main trunk of the radial artery now passes into the palm between the oblique and transverse heads of the adductors of the thumb to form the deep palmar arch.
The deep palmar arch is an arterial arch formed by the terminal branch of the radial artery that anastomoses with the deep branch of the ulnar artery. Unlike the shallow angle, the deep hook is usually complete.
The radial artery gains the palm as it passes between the oblique and transverse heads of the adductor muscle and runs through the palm at approximately 1 cm proximal to the superficial arch.
The deep branch of the ulnar nerve lies within the concavity of the deep arch.
From its convexity, three palmar metacarpal arteries pass distally, and in the region of the metacarpal heads, they anastomose with the common palmar digital branches of the superficial arch.
The branches pierce the interosseous spaces to anastomose with the dorsal metacarpal arteries.
The accompanying veins drain most of the blood from the palm to the dorsal venous network.
For a visual assessment of the contribution of the radial and ulnar arteries to the blood supply of the hand, make a closed fist and occlude the radial and ulnar arteries.
When the fist is released, the skin on the palm appears pale, but the color should return quickly as one of the arteries is released.
