What term describes the process of expanding blood vessels?

The term that describes the process of expanding blood vessels is vasodilation. This biological process involves the relaxation of the smooth muscle tissue within the blood vessel walls, leading to an increase in the diameter of the vessels. This expansion can enhance blood flow to various tissues and is crucial in regulating blood pressure and temperature, as well as facilitating healing by increasing the supply of oxygen and nutrients to affected areas.

Hyperemia refers to an excess of blood in a particular area, resulting from vasodilation but is not the process itself. Vasoconstriction, on the other hand, is the narrowing of blood vessels, which reduces blood flow. Angiogenesis is the formation of new blood vessels from pre-existing ones, a different process altogether that is more about growth and development rather than the immediate action of expanding existing vessels.