The human body relies on a complex network of vessels to transport blood, oxygen, and nutrients to every cell. Arteries are a fundamental part of this system, acting as specialized blood vessels that carry oxygen-rich blood away from the heart to the rest of the body. Their robust, elastic walls allow them to withstand and maintain the high pressure generated by the heart’s pumping action, ensuring efficient delivery of these life-sustaining components.
The Body’s Main Artery: The Aorta
The largest artery in the human body is the aorta, which originates directly from the left ventricle of the heart. It begins by ascending, then arches over the top of the heart, and finally descends through the chest and abdomen. This continuous vessel is divided into four main sections: the ascending aorta, the aortic arch, the thoracic aorta, and the abdominal aorta.
The ascending aorta gives rise to the coronary arteries, which supply blood to the heart muscle itself. From the curved aortic arch, three major arteries branch off to supply the upper body and head: the brachiocephalic trunk, the left common carotid artery, and the left subclavian artery. The brachiocephalic trunk further divides into the right common carotid artery and the right subclavian artery, serving the right side of the head, neck, and right upper limb.
Arteries of the Upper Body and Head
The common carotid arteries are vessels that travel up each side of the neck. The left common carotid originates directly from the aortic arch, while the right common carotid arises from the brachiocephalic trunk. These arteries do not branch within the neck, but each common carotid artery divides into an internal and external carotid artery.
The internal carotid arteries supply the brain and eyes, while the external carotid arteries deliver blood to the face, neck, and scalp. The subclavian arteries, located beneath the collarbones, provide blood to the arms, neck, and parts of the chest wall.
As the subclavian artery extends into the armpit, it becomes the axillary artery, which then transitions into the brachial artery in the upper arm. In the forearm, the brachial artery divides into the radial and ulnar arteries, supplying the lower arm and hand. These arteries are accessible for pulse points, such as the radial artery at the wrist.
Arteries of the Lower Body
The abdominal aorta, the final segment of the aorta, descends through the abdomen and divides into two large arteries, the common iliac arteries. These common iliac arteries then split into internal and external iliac arteries. The internal iliac arteries supply blood to the pelvic organs and gluteal region.
The external iliac arteries continue into the lower limbs, becoming the femoral arteries as they pass under the inguinal ligament in the thigh. The femoral artery is a prominent artery in the thigh, and its pulse can be felt in the groin area. Behind the knee, the femoral artery changes its name to the popliteal artery, which supplies the knee joint and lower leg.
Further down the leg, the popliteal artery branches into the anterior and posterior tibial arteries. These arteries provide blood to the lower leg and foot. The posterior tibial artery, for instance, can be palpated behind the inner ankle.
The Critical Role of Arteries
Arteries’ muscular and elastic walls allow them to expand and contract with each heartbeat, maintaining consistent blood pressure throughout the circulatory system. This continuous, high-pressure flow ensures oxygenated blood reaches all body parts efficiently. Arteries also regulate blood flow by adjusting their diameter, meeting the varying demands of different organs and maintaining circulatory health.