What are arterioles, venules, and capillaries collectively known as?

Arterioles, venules, and capillaries are collectively known as microcirculation because they are the small blood vessels responsible for the exchange of nutrients, gases, and waste products at the tissue level. Microcirculation refers specifically to the smaller vascular components that cater to the immediate cellular environment, facilitating vital functions such as the delivery of oxygen and nutrients as well as the removal of carbon dioxide and metabolic waste. This intricate network plays a crucial role in maintaining tissue health and is integral to how blood flow is regulated within organs and tissues.

The other terms, though related to the circulatory system, do not accurately describe the collective function and structure of arterioles, venules, and capillaries. Macro circulation typically refers to the larger blood vessels like arteries and veins that transport blood over longer distances throughout the body. Blood vessels is a broad term that includes all types of vessels but does not specifically denote the microvascular components. Capillary network refers specifically to the arrangement of capillaries but omits arterioles and venules from its definition.