Artery

An artery is a blood vessel that carries blood away from the heart to the body’s tissues and organs. Most arteries carry oxygenated blood: the left side of the heart pumps oxygen-rich blood into the aorta, the largest artery in the body, which branches progressively into smaller arteries, arterioles and finally capillaries throughout the body. The exception is the pulmonary artery, which carries deoxygenated blood from the right ventricle to the lungs.

Arteries are built to withstand high pressure. Their walls have three layers: an inner endothelial lining, a muscular middle layer (tunica media) and an outer connective tissue layer (tunica adventitia). The muscular layer allows arteries to contract (vasoconstriction) and relax (vasodilation) to regulate blood flow and pressure. Larger arteries near the heart, such as the aorta, also contain elastic fibres that allow them to stretch during systole and recoil during diastole, smoothing blood flow into a steady stream.

The coronary arteries are the most clinically significant arteries for SCA UK’s audience. They arise from the base of the aorta immediately above the aortic valve and supply the heart muscle itself with the oxygen and nutrients it needs to pump continuously. Disease of the coronary arteries (coronary artery disease) due to atherosclerosis is the most common cause of heart attack and a major cause of sudden cardiac arrest in adults. When a coronary artery is acutely blocked, the area of heart muscle it supplies begins to die within minutes.

Other arteries affected by cardiovascular disease include the carotid arteries (supplying the brain, relevant to stroke risk), the renal arteries (supplying the kidneys, relevant to hypertension management) and the peripheral arteries of the legs (peripheral arterial disease). Management of arterial disease generally centres on controlling risk factors including blood pressure, cholesterol, blood glucose and smoking, alongside antiplatelet therapy and, where indicated, revascularisation procedures.