The vessels of the arms are part of the circulatory system, which provides nutrients to the tissues. The arteries deliver freshly oxygenated blood to muscles and bone. The veins return oxygen-depleted blood to the heart.
Oxygenated blood begins its journey into the arm by leaving the aortic arch and passing into one of two subclavian arteries. These travel under the collarbones of each shoulder and down the arms. They branch out further to form other arteries:
- Brachial artery: The brachial artery is the major artery of the upper arm. It travels down the upper arm and through the elbow. It then divides into the radial and ulnar arteries.
- Radial artery: This artery splits from the brachial artery to follow the radius bone on the thumb side of the forearm.
- Ulnar artery: Opposite of the radial artery, this artery follows the ulna bone in the forearm on the “pinkie” finger side of the forearm.
- Deep palmar arch: This series of arteries forms where the ulnar and radial arteries meet at the palm of the hand. This semicircular artery branches into the arteries of the fingers, which are known as palmar digital branches.
Whereas the arteries of the human arms form a clean loop-like distribution system for oxygenated blood, the veins that carry oxygen-depleted blood back to the heart create a more intricate web-like drainage system.
Some of the veins in the arm include:
- Dorsal venous network: This web of veins extends across the back of the hand.
- Superficial veins: As their name implies, these veins are close to the skin’s surface. These veins are only present in the extremities and are easily detected in the back of the hand and the forearm in most people.
- Cephalic vein: This large vein travels through the upper arm before branching near the elbow and into the forearm. It is often easily seen through the skin in the biceps region.
- Basilic vein: Opposite the cephalic vein, the basilic vein travels through the arm near the triceps muscle on the underside of the arm.
Damage to these major veins and arteries, especially trauma to the forearm, can be fatal.