It is one of the terminal branches of the brachial artery. It begins, a little below the bend of the elbow (knee joint), in the cubital fossa (triangular area in front of the knee joint). It runs along the radial side (lateral side) of the whole length of the forearm to the wrist. From wrist, it turns posteriorly, along lateral side of carpus and enters the anatomical snuff box (triangular deepening on the radial, dorsal aspect of the hand). Finally, it passes forward between the two heads of the first interosseus dorsalis muscle and enters into the palm of the hand. There, it passes above the metacarpal bones and reaches the medial side of the hand. Here, it unites with the deep branch of the ulnar artery to form deep palmar arch (which supplies the part of the hand and fingers). So the radial artery, based on its course, is divided into three parts, one is in the forearm, second at the back of the hand and third in the hand.

RELATIONS

In the forearm:

Along its course, it is accompanied by two venae comitantes. Anteriorly, in the upper part is brachioradialis and lower part is only covered by skin and fascia. Posterior to it, muscles attached to anterior surface of radius bone. Laterally, brachioradialis muscle and radial nerve are present. Medially, in the upper part pronator teres muscle and in the lower part the tendon of flexor carpi radialis is present.

On dorsum of hand and in palm:

While passing through the anatomical snuff box, anteriorly, the tendons of abductor pollicis longus, extensor pollicis brevis and pollicis longus are present. At the wrist, inferiorly, lateral ligament of wrist joint, scaphoid and trapezium are present. In the palm, proximally and anteriorly, oblique head of the adductor pollicis muscle is present.

BRANCHES

In the forearm:

• The radial recurrent artery

• Muscular branches

• The palmar carpal branch

• The superficial palmar branch (by joining to superficial branch of ulnar artery forms superficial palmar arch )

On dorsum of hand and in palm:

• A branch to lateral side of the dorsum of the thumb

• The first dorsal metacarpal artery

• The princeps pollicis artery

• The radialis indicis artery

AREAS SUPPLIED BY THE RADIAL ARTERY

All these branches supply the area around the elbow (knee joint), flexor and extensor muscles of lateral side of the forearm and finally to the structures of the hand (in hand supplies with ulnar artery).

THE RADIAL PULSE

It is the most common artery that is used to notice the heart rate and rhythm. It is used commonly because it is easily accessible, comparison of the two radial arteries can be done to find out any abnormality, it is almost directly in line with the heart.

It is palpated at wrist joint, on thumb’s side of the hand, at the base of the thumb. It can also be palpated in the anatomical snuff box, at the back of the thumb.