Vasodilation means the smooth muscles in your blood vessel walls relax causing them to widen. This widening results in less vascular resistance, thus the blood flowing through the dilated vessel increases. Vasodilation may occur locally or system wide.
Some basic health benefits resulting from vasodilation include:
- lowering blood pressure
- assists in eliminating excess metabolic produced heat
- enhances clotting factor & leukocyte entry into damage tissue
- increases delivery of oxygen & nutrients during energy consuming activities
The natural signals for causing vessels to dilate are referred to as vasodilators and the source varies, including parasympathetic nerve impulses, hormones and bradykinin release. The term vasodilator is also used in reference to drugs that treat certain conditions that benefit from vasodilation, such as hypertension, angina, congestive heart failure, pulmonary hypertension and erectile dysfunction.
Vasoconstriction means the smooth muscles in your blood vessel walls contract causing them to narrow. This action results in blood flow through your vessels to be restricted. Some health benefits of vasoconstriction are:
- retain heat in cold climates
- reduce excessive blood loss
- prevent orthostatic hypotension
Vasoconstriction can be caused by sympathetic nerve impulses, prostaglandins, serotonin and epinephrine. Certain drugs can also stimulate blood vessels to constrict, referred to as vasoconstrictors or vasopressors, for instance:
Caffeine causes vasoconstriction as well.
