Artery Function

Arteries are blood vessels that carry blood away from the heart under pressure. This blood is usually oxygenated, with the exception of that in the pulmonary artery, which carries deoxygenated blood to the lungs.

Arterial system

Simplified diagram of the human arterial system in anterior view.

This diagram of the arterial system indicates the anterior, middle, and posterior cerebral arteries; basilar artery; internal and external carotid arteries; vertebral arteries; common carotid arteries; pulmonary veins; heart; intercostal arteries; left and right gastric arteries; celiac trunk; splenic artery; common hepatic artery; superior and inferior mesenteric artery; renal artery; testicularis artery; common, internal, and external iliac arteries; femoral circumflex artery; perforating branch; deep femoral artery; femoral artery; popliteal artery; dorsal metatarsal and digital arteries; arcuate artery; deep plantar arch; peroneal artery; posterior and anterior tibial artery; inferior, superior, and descending genicular arteries; descending branch of the femoral circumflex artery; digital artery; deep palmar arches; dorsal and palmar carpal arch; ulnar artery; radial artery; interosseous artery; inferior and superior epigastric artery; descending aorta; radial recurrent artery; deep brachial artery; brachial artery; internal thoracic artery; axillary artery; aortic arch; and subclavian artery.

As with veins, arteries are comprised of three layers: the tunicae intima, media, and externa. In arteries, the tunica media, which contains smooth muscle cells and elastic tissue, is thicker than that of veins so it can modulate vessel caliber and thus control and maintain blood pressure.

Arterial pressure varies between the peak pressure during heart contraction, called the systolic pressure, and the minimum or diastolic pressure between contractions, when the heart expands and refills. This pressure variation within the artery produces the observable pulse that reflects heart activity. The pressure in the arterial system decreases steadily, highest in the aorta and lowest in the venous system, as blood approaches the heart after delivery of oxygen to tissues in the systemic circulation.

Arteries of the systemic circulation can be subdivided into muscular or elastic types according to the the relative compositions of elastic and muscle tissue in their tunica media. Larger arteries are typically elastic and smaller arteries are more likely to be muscular. These arteries deliver blood to the arterioles, which in turn deliver blood to the capillary networks associated with the body's tissues.