BLOOD SUPPLY OF FOREARM
The brachial artery divides into radial and ulnar arteries. Their named branches lie near the elbow and wrist, and only unnamed muscular branches arise in the middle forearm.
This smaller branch continues the direct line of the brachial artery, ending at the wrist at the “pulse position.” It first crosses the tendon of the pronator teres muscle and descends adjacent to the superficial branch of the radial nerve. It branches into the radial recurrent artery and muscular, palmar carpal, and superficial palmar branches.
The radial recurrent artery arises shortly below the origin of the radial artery. Ascending on the supinator muscle, the artery supplies this muscle and the brachioradialis and brachialis muscles and anastomoses with the radial collateral artery (see Plate 3-8).
Muscular branches supply the muscles of the radial side of the forearm. The palmar carpal branch arises near the distal border of the pronator quadratus muscle. It ends by anastomosing with the palmar carpal branch of the ulnar artery, the termination of the anterior interosseous artery, and recurrent branches of the deep palmar arterial arch.
The superficial palmar branch leaves the radial artery just before it turns from the radial border of the wrist onto the back of the hand. It descends over or through the muscles of the thumb and joins the superficial branch of the ulnar artery to form the superficial palmar arterial arch.
This larger branch describes a gentle curve to the ulnar side of the forearm. It passes deep to both heads of the pronator teres and all the other superficial flexor muscles of the forearm and is crossed by the median nerve. It lies deep to the flexor carpi ulnaris muscle and enters the hand in company with the ulnar nerve.
The anterior ulnar recurrent artery turns upward from just below the elbow joint between the brachialis and pronator teres muscles. It supplies these muscles and anastomoses with the anterior branches of both ulnar collateral arteries.
The posterior ulnar recurrent artery, larger than the anterior, arises near or in common with it. It ascends between the flexor digitorum superficialis and flexor digitorum profundus muscles to supply the elbow joint. It ends in anastomoses with posterior branches of both ulnar collateral arteries and the interosseous recurrent artery and in the network of the olecranon.
The common interosseous artery arises from the radial side of the ulnar artery and divides into anterior and posterior interosseous arteries. The anterior interosseous artery descends on the anterior surface of the interosseous membrane as far as the upper border of the pronator quadratus muscle in company with veins and the anterior interosseous branch of the median nerve. It gives off nutrient arteries to the radius and ulna and a long slender median artery to the palm. At the upper border of the pronator quadratus muscle, a small palmar carpal branch is given off. The artery terminates in the dorsal carpal network.
The posterior interosseous artery passes to the back of the upper forearm, emerging between the supinator and abductor pollicis longus muscles with the deep branch of the radial nerve. Sending twigs to the extensor muscles of the forearm, it descends to anastomose with the dorsal terminal branch of the anterior interosseous artery. An interosseous recurrent branch ascends deep to the supinator and anconeus muscles to the interval between the lateral epicondyle of the humerus and the olecranon; there, it communicates with the middle collateral, inferior ulnar collateral, and posterior ulnar recurrent arteries.
Muscular branches of the ulnar artery reach the muscles of the ulnar side of the forearm. The palmar carpal branch arises at the upper border of the flexor retinaculum, passes across the wrist deep to the flexor tendons, and unites with the palmar carpal branch of the radial artery. The dorsal carpal branch arises just above the pisiform. It winds around the border of the wrist, deep to the tendons, to help form the dorsal carpal arterial arch.