What is the role of resistance vessels like arterioles?

Resistance vessels, particularly arterioles, play a crucial role in regulating peripheral resistance and blood pressure within the circulatory system. They are characterized by their ability to constrict and dilate in response to various physiological demands. This ability allows them to control the flow of blood to different tissues, thus ensuring that areas with higher metabolic needs receive an adequate blood supply while also influencing overall vascular resistance.

By regulating vascular tone, arterioles can increase or decrease blood flow, which directly affects systemic blood pressure. When arterioles constrict, there is an increase in peripheral resistance, resulting in elevated blood pressure. Conversely, when they dilate, peripheral resistance decreases, leading to lower blood pressure. This dynamic regulation is essential for maintaining homeostasis and allowing the body to respond appropriately to changes in activity level, temperature, and other metabolic demands.

While gas exchange occurs in capillaries, oxygen storage is primarily a function of hemoglobin in red blood cells, and the transport of metabolic waste is mainly handled by capillaries leading to venules and veins. Therefore, the specific and significant role of arterioles as resistance vessels highlights their importance in regulating blood flow and pressure in the vascular system.