arteres

Arteries are blood vessels that carry blood away from the heart to tissues throughout the body. In the systemic circulation they transport oxygen-rich blood, while the pulmonary arteries move blood from the heart to the lungs to be oxygenated. Arterial walls are thicker and more elastic than those of veins, to withstand higher pressure and to help propel blood forward between heartbeats.

An artery’s wall typically consists of three layers: the tunica intima, a smooth inner lining; the tunica media, containing smooth muscle and elastic fibers; and the tunica adventitia, an outer connective tissue layer. Elastic arteries near the heart (such as the aorta) have many elastin fibers to absorb pulse waves; muscular arteries have more smooth muscle to regulate flow and pressure; arterioles are the smallest arteries that deliver blood to capillary beds.

Blood flow in arteries is regulated by autonomic nerves and local chemical signals that cause dilation or constriction of the vessel. The endothelium, the inner lining, also releases substances such as nitric oxide that promote relaxation and reduce resistance.

Healthy arteries are essential for adequate tissue perfusion. Diseases affecting arteries include atherosclerosis, hypertension, aneurysms, and peripheral artery disease, which can reduce blood flow or rupture. Risk factors include smoking, high cholesterol, diabetes, obesity, and age. Diagnosis commonly uses blood pressure measurements, imaging, and angiography, while treatment ranges from lifestyle changes to medications and procedures that restore or improve blood flow.