Resistance artery

Resistance Arteries are small diameter blood vessels in the microcirculation that act as the primary regulators of systemic vascular resistance. They play a crucial role in controlling blood pressure and blood flow distribution.

Structure

Resistance arteries are typically less than 0.5 mm in diameter and are composed of three layers: the tunica intima, tunica media, and tunica adventitia. The tunica media of resistance arteries is primarily composed of smooth muscle cells, which are responsible for the contractile properties of these vessels.

Function

The primary function of resistance arteries is to regulate blood flow to different parts of the body. They achieve this by constricting or dilating in response to various signals, including neural input, hormones, and local metabolites. This ability to change diameter, known as vasomotion, allows resistance arteries to control the resistance to blood flow, thereby influencing blood pressure and blood flow distribution.

Clinical significance

Abnormalities in the function of resistance arteries can lead to various cardiovascular diseases, including hypertension, atherosclerosis, and heart failure. For example, increased constriction or decreased dilation of resistance arteries can lead to increased vascular resistance, which can result in hypertension.

Research

Research on resistance arteries is focused on understanding the mechanisms that regulate their function and how these mechanisms are altered in disease. This research is important for the development of new treatments for cardiovascular diseases.

See also

• Artery
• Blood vessel
• Microcirculation
• Vascular resistance
• Vasomotion