Artery

An artery is a blood vessel.

Function of arteries

An artery is a blood vessel which transports blood from the heart to the organs, whereas veins transport blood from the organs to the heart.

While in general blood in arteries is more highly oxygenated than blood in veins, there are exceptions. The pulmonary artery leaves the heart to the lungs where the blood is loaded with oxygen. The pulmonary veins return the blood that has been freshly enriched with oxygen to the heart in order for it to be redistributed throughout the body.

Structure of arteries

Arteries are formed from three superimposed layers:

• the intima, an endothelium in contact with the blood;
• the media, formed from elastic tissues (muscle, elastin);
• and the adventitia, the fibrous rigid peripheral layer (collagen).

The further an artery is from the heart, the smaller is its calibre.