What is the term for the intermittent contraction and relaxation of metarterioles?

The term for the intermittent contraction and relaxation of metarterioles is vasomotion. This phenomenon plays a crucial role in regulating blood flow and perfusion within the microcirculation. It involves rhythmic changes in the diameter of the metarterioles, which are small blood vessels that connect arterioles to capillaries.

The contraction and relaxation of these vessels help to modulate the volume of blood flowing into the capillary networks, thereby influencing tissue perfusion rates. Vasomotion is largely driven by the smooth muscle cells in the vessel walls and can be influenced by various factors such as tissue demand for oxygen, local metabolic processes, and neural or hormonal signals.

Understanding vasomotion is essential for cardiovascular perfusionists, as it informs how blood supply can be adjusted in response to the metabolic needs of tissues, particularly during surgical procedures where these dynamics may be altered.