Arteries of the forearm and hand

Radial artery

The radial artery (a. radialis) branches off from the brachial artery in the cubital fossa and runs inferiorly and laterally. Initially, it lies on the anterior surface of the pronator teres, then descends between the brachioradialis and the flexor carpi radialis. In the lower third of the forearm, the vessel is covered only by fascia and skin—here it is easily compressed against the radius to check the pulse.

Further down, the artery courses dorsally, lying over the bones of the anatomical snuffbox (over the scaphoid bone), passes beneath the tendon of the extensor pollicis longus, and enters the palm through the first interosseous space. In the hand, it is the primary contributor to the deep palmar arch.

Key branches:

• Radial recurrent artery (a. recurrens radialis) — ascends toward the lateral epicondyle, forming the elbow network.
• Superficial palmar branch (r. palmaris superficialis) — crosses the thenar eminence and merges into the superficial arch.
• Carpal branches (palmar and dorsal) — participate in the carpal networks.
• Princeps pollicis artery (a. princeps pollicis) — divides into two arteries for the thumb.
• Radialis indicis artery (a. radialis indicis).

Ulnar artery

The ulnar artery (a. ulnaris) is usually the larger terminal trunk of the brachial artery. From the cubital fossa, it runs medially and anteriorly, passing beneath the pronator teres. In the forearm, it runs between the flexor digitorum superficialis and flexor digitorum profundus, and in the middle and lower thirds, within the groove between the flexor carpi ulnaris and the flexor digitorum superficialis. In its distal part, the ulnar nerve joins it.

The artery enters the palm anterior to the pisiform bone, lying superficial to the palmar aponeurosis, and continues as the base of the superficial palmar arch.

Key branches:

• Ulnar recurrent artery (a. recurrens ulnaris) — gives off anterior and robust posterior branches to the medial epicondyle.
• Common interosseous artery (a. interossea communis) — a short trunk that divides into the anterior (running on the interosseous membrane) and posterior (passing to the dorsal forearm) interosseous arteries.
• Deep palmar branch (r. palmaris profundus) — crosses the palm beneath the tendons and completes the deep arch.

Palmar arches and vascular networks

Two powerful arterio-arterial anastomoses form in the hand, protecting the fingers from ischemia during gripping movements:

1. Superficial palmar arch (arcus palmaris superficialis). Formed primarily by the ulnar artery with a contribution from the superficial branch of the radial artery. It lies beneath the aponeurosis. It gives off three common palmar digital arteries, which divide into proper digital arteries for the adjacent sides of digits II–V.
2. Deep palmar arch (arcus palmaris profundus). The main contributor is the radial artery, completed by the deep branch of the ulnar artery. Located deeper, at the bases of the metacarpal bones. It gives rise to palmar metacarpal arteries (reinforcing the superficial arch) and perforating branches to the dorsum of the hand.

In addition to the arches, the following are distinguished in the forearm and hand region:

• Elbow joint network (rete articulare cubiti) — connects the collateral arteries of the arm with the recurrent branches of the radial, ulnar, and interosseous arteries.
• Dorsal carpal network (rete carpi dorsale) — formed by the dorsal carpal branches of both major vessels and the posterior interosseous artery. It gives rise to the dorsal metacarpal arteries.

Class and exam questions

What else to study on this topic

• Topography of the branches of the common interosseous artery in the forearm
• Formation and anastomoses of the dorsal carpal network
• Syntopy of arteries and nerves in the lower third of the forearm
• Role of the perforating branches of the deep palmar arch
• Anastomoses of the ulnar articular network

Other topics in the "Angiology" section

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