increase in the internal diameter of blood vessels due to relaxation of smooth muscle cells

Vasodilation is where blood vessels widen.[1] It results from relaxation of muscle cells within blood vessel walls. The process is essentially the opposite of vasoconstriction, which is the narrowing of blood vessels.

Diagram of blood vessels.

When vessels widen, blood flow is increased. This in turn decreases blood pressure. Drugs that cause vasodilation are called vasodilators.

References change

  1. "Definition of Vasodilation". 27 April 2011. Archived from the original on 5 January 2012. Retrieved 13 January 2012.