What is the Radial Artery?

The brachial artery is the main blood supply for the arm. It begins right around the axilla or armpit and continues to the elbow. From there, it splits into two branches: the ulnar and radial arteries. The radial artery lies on the lateral side of the forearm, running from the elbow down to the thumb and continuing into the hand.

The radial artery has an interesting path that demonstrates how important it is to blood flow in the forearm. It begins at the inner elbow and travels to the wrist. Then, it winds around the back of the hand and beneath the tendons that move the thumb. From there, it heads between the thumb and pointer finger metacarpal bones in the hand before making its way deep into the palm.

The forearm is composed of two bones, the radius and the ulna. Not surprising, the radial artery follows the radius and the ulnar artery follows the ulna, on opposite sides of the forearm. Each artery branches off and travels around the wrist and hand. They meet in the palm and fuse to form the superficial and deep palmer arches that supply the hand, as well as the digital arteries that supply the fingers.

If the radial artery suffers damage near the wrist from a medical procedure or trauma, the ulnar artery can take over perfusion of the hand. The ulnar artery is larger than the radial artery and, since the two meet in the palm, there is still a clear path for blood to enter the hand.

The radial artery has a lot of branches that supply blood to different areas of the forearm as the vessel makes its way from the elbow, around the hand, and into the palm. Specifically, it provides blood to the index finger, thumb, carpal bones, nerves in the wrist, muscles in the lateral forearm, radial nerve, and elbow joint.

All arteries carry blood from the heart to the rest of the body. In the arm, oxygenated, nutrient-rich flows into the brachial artery and then into the radial and ulnar arteries. From there, the branches and small vessels arising from both the radial and ulnar artery deliver oxygen and nutrient-rich blood to the entire forearm and hand.

A coronary artery bypass graft or CABG bypasses blockages to the heart. The radial artery is one of the vessels commonly harvested and used as a graft in this life-saving procedure because it is easy to access and, as long as the ulnar artery is functioning properly, removal will not compromise blood supply to the hand.

For procedures such as cardiac catheterization or stent placement, the most common approach is to insert the catheter probe through the femoral artery of the leg. This can be a problem if the femoral artery is not accessible, which can occur for various reasons such as obesity. The radial artery is a great alternative because it is easy to access and, if damage occurs, repairs are fairly simple and the ulnar artery can compensate if needed.

The radial artery runs close to the surface at the wrist, which is why it is the artery most commonly used to assess pulse. Simply place the pads of two to three fingers over the tendon and the bone over the radial artery. The bounding of the radial pulse is not difficult to feel and record.

An arterial blood gas or ABG test measures oxygen, carbon dioxide, and pH. It is usually only performed in a hospital setting because the results help diagnose a range of serious health problems, including lung failure, kidney failure, asthma, COPD, shock, or chemical poisoning. The blood for this test is most commonly taken from the radial artery by a doctor.