Vasodilation
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.
![](http://up.wiki.x.io/wikipedia/commons/thumb/d/d3/Blood_vessels-en.svg/220px-Blood_vessels-en.svg.png)
When vessels widen, blood flow is increased. This in turn decreases blood pressure. Drugs that cause vasodilation are called vasodilators.
References
change- ↑ "Definition of Vasodilation". MedicineNet.com. 27 April 2011. Archived from the original on 5 January 2012. Retrieved 13 January 2012.