Topic Overview

Arteries of the Front of Forearm

Overview

• The blood supply of the anterior compartment of the forearm is derived mainly from:

  • Radial artery

  • Ulnar artery

• Both are terminal branches of the brachial artery in the cubital fossa.

• These arteries provide major contributions to the palmar arches in the hand.

Radial Artery

Origin

• One of the two terminal branches of the brachial artery in the cubital fossa.

Course

1. Begins in cubital fossa opposite the neck of radius.

2. Runs down the lateral side of forearm under cover of brachioradialis.

3. Lies on supinator, flexor pollicis longus, and pronator quadratus.

4. In the lower third of forearm → becomes superficial, lying between tendons of brachioradialis and flexor carpi radialis.

5. Passes across lateral aspect of wrist, winds dorsally around lateral side of carpus, through anatomical snuffbox.

6. Then passes between heads of first dorsal interosseous muscle to reach the palm → forms deep palmar arch.

Branches in Forearm

1. Radial recurrent artery → ascends to anastomose with radial collateral artery (from profunda brachii).

2. Muscular branches → to adjacent muscles.

3. Palmar carpal branch → participates in palmar carpal arch.

4. Superficial palmar branch → joins ulnar artery to form superficial palmar arch.

5. Dorsal carpal branch → contributes to dorsal carpal arch.

Relations

• Lateral: Brachioradialis (upper part), radial styloid (lower part).

• Medial: Tendon of flexor carpi radialis.

• Posterior: Supinator, pronator teres, flexor pollicis longus, pronator quadratus.

• Anterior: Skin, fascia, and superficial veins.

Clinical Anatomy

• Radial pulse → felt just lateral to tendon of flexor carpi radialis.

• Used for arterial blood sampling and cannulation due to superficial location.

• Allen’s test: used to check patency of radial and ulnar arteries before radial artery puncture.

• Wound in snuffbox: may injure radial artery → risk of hemorrhage.

• Used for coronary artery grafting (radial artery graft).

Ulnar Artery

Origin

• Terminal branch of brachial artery in cubital fossa.

Course

1. Passes deep to pronator teres and flexor digitorum superficialis.

2. Runs downward on the medial side of forearm accompanied by the ulnar nerve (in lower one-third).

3. Enters hand anterior to flexor retinaculum, lateral to pisiform bone, through the ulnar canal (Guyon’s canal).

4. Terminates by forming the superficial palmar arch (main contributor).

Branches in Forearm

1. Common Interosseous Artery

• Short trunk from upper part of ulnar artery; divides into:

  • Anterior interosseous artery → runs on interosseous membrane with anterior interosseous nerve; supplies deep flexors.

  • Posterior interosseous artery → passes above interosseous membrane to posterior compartment; anastomoses with recurrent branches around elbow.

2. Ulnar Recurrent Arteries

• Anterior ulnar recurrent → joins inferior ulnar collateral.

• Posterior ulnar recurrent → joins superior ulnar collateral (behind medial epicondyle).

3. Muscular Branches

• Supply superficial and deep flexors.

4. Palmar and Dorsal Carpal Branches

• Form small arterial networks at wrist.

5. Terminal Branch

• Forms the superficial palmar arch, which mainly supplies fingers.

Relations

• Upper part: Deep to both heads of pronator teres and flexor digitorum superficialis.

• Lower part: Lies between flexor carpi ulnaris (medial) and flexor digitorum superficialis (lateral).

• Accompanied by: Ulnar nerve (in distal one-third).

• At wrist: Lies lateral to pisiform and ulnar nerve.

Clinical Anatomy

• Ulnar pulse → felt lateral to pisiform bone (difficult to palpate due to depth).

• Allen’s test used to evaluate adequacy of collateral circulation.

• Injury to ulnar artery in Guyon’s canal → may be associated with ulnar nerve damage.

• Ulnar artery thrombosis (Hypothenar hammer syndrome) in manual workers due to repetitive trauma.

Dissection of Arteries of Front of Forearm

Steps

1. Expose the cubital fossa and identify the brachial artery bifurcation into radial and ulnar arteries.

2. Trace the radial artery beneath brachioradialis along the lateral forearm.

3. Note the radial recurrent artery ascending toward lateral epicondyle.

4. Identify the ulnar artery deep to pronator teres and FDS.

5. Follow the common interosseous artery and its anterior and posterior branches on either side of the interosseous membrane.

6. In lower third of forearm, observe ulnar artery with ulnar nerve emerging from under flexor carpi ulnaris.

7. At wrist, identify:

   • Radial artery lateral to flexor carpi radialis tendon.

   • Ulnar artery lateral to pisiform bone.