The brachial artery is the primary blood vessel that carries oxygenated blood to the entire upper arm, supplying nutrients to the limb. This major artery is the continuation of the axillary artery, which travels through the armpit. It begins at the lower edge of the large muscle known as the teres major, which is located near the shoulder. From this starting point, the brachial artery descends down the inner side of the arm until it reaches the elbow. Healthy blood flow through this vessel is important for the function of the forearm and hand.
Defining the Brachial Artery’s Location
The brachial artery begins where the axillary artery passes the bottom border of the teres major muscle. It travels down the anterior compartment of the upper arm, running along the medial side of the humerus. Its path is relatively straight, lying between the biceps brachii and the triceps brachii muscles, making it somewhat protected.
As the artery descends, it maintains a close anatomical relationship with the median nerve, a major nerve of the arm. Initially, the median nerve is positioned to the side of the artery, but as they move down the arm toward the elbow, the nerve crosses over to lie directly in front of the artery. This arrangement places the artery near the skin’s surface at the elbow crease, which is a significant factor in its medical relevance.
The artery terminates at the elbow region in a space known as the cubital fossa, which is the soft, triangular hollow at the front of the elbow. It ends approximately one centimeter below the elbow joint, at the level of the neck of the radius bone. Here, the single brachial artery splits into its two terminal branches, continuing blood supply into the forearm.
The Primary Role in Upper Limb Circulation
The brachial artery delivers oxygen-rich blood and nutrients to the entire upper limb. It supplies the muscles of the upper arm directly and branches off to feed structures further down the arm. The specific muscles nourished by the brachial artery and its branches include the biceps brachii, the triceps brachii, and the coracobrachialis.
The largest branch is the deep brachial artery (profunda brachii artery). This branch travels backward, running along the humerus with the radial nerve, to supply the muscles in the posterior compartment of the arm, such as the triceps. Smaller vessels, including the superior and inferior ulnar collateral arteries, also emerge to contribute to a network around the elbow joint.
Oxygenated blood is passed on to the forearm and hand through the final division of the brachial artery. At the cubital fossa, the vessel bifurcates, or splits, into the radial and ulnar arteries. These two arteries run parallel down the forearm, ensuring blood supply continues to the wrist and hand.
Why the Brachial Artery Matters in Medicine
The location of the brachial artery, particularly where it runs close to the surface near the elbow, makes it important in medical practice. Its most common use is as the primary site for measuring blood pressure using a cuff and stethoscope. The cuff is placed around the upper arm, directly over the artery, to temporarily compress the vessel and allow for the detection of blood flow sounds.
The brachial artery is also a reliable site for checking a pulse, particularly in infants or during emergency situations. The pulse is felt on the inside of the arm, near the elbow crease, by pressing lightly against the bone, which confirms blood circulation to the limb. This accessibility makes it a common diagnostic point for assessing a patient’s circulatory status.
Beyond routine checks, the artery is sometimes used as an access point for certain interventional procedures, such as cardiac catheterization. Physicians can insert a catheter into the brachial artery at the elbow and guide it through the body’s vascular system to reach the heart. This technique allows for the diagnosis and treatment of conditions like blockages or aneurysms without the need for open surgery.