elasticarterier

Elastic arteries, also known as conducting arteries, are the largest arteries in the circulatory system. They include the aorta and its major branches, the pulmonary trunk, and other proximal arteries. Their defining feature is a tunica media rich in elastic fibers, organized into many concentric lamellae that permit marked elasticity. The intima is thin and lined by endothelium, and the adventitia provides structural support and houses the vasa vasorum in most segments.

The abundant elastic tissue enables the Windkessel effect, allowing these arteries to expand during systole as the heart ejects blood and then recoil during diastole to maintain continuous flow and arterial pressure. This buffering reduces peak systolic pressure downstream and lowers pulsatile stress on smaller vessels.

Elastic arteries exhibit a high density of elastic lamellae in the tunica media, with smooth muscle cells interspersed between lamellae. The vasa vasorum is present mainly in the adventitia, supplying the outer portions of the wall. They are more distensible than muscular arteries, and their relative media thickness reflects their role as pressure reservoirs rather than primary resistance vessels.

Clinical relevance includes age-related degradation of elastic fibers reducing arterial compliance, contributing to increased pulse pressure and systolic hypertension. Aneurysms frequently involve elastic arteries, especially the aorta. Conditions such as Marfan syndrome can affect the structural integrity of elastic tissue and connective components. Atherosclerosis tends to affect the intima, but loss of elasticity can exacerbate vascular disease.

Examples include the aorta (ascending and thoracic portions), the pulmonary arteries, and other proximal arteries such as certain carotid segments.