How does blood volum e affect blood flow?

Answer 1

Blood vessels alter blood flow by vasoconstriction and vasodilation. Chemicals that mediate vasoconstriction include serotonin and norepinephrine among others. Vasoconstriction works by contraction of smooth muscle lining the vessel walls and narrowing of the lumens of vessels, increasing blood pressure, but also increasing resistance. Chemicals that mediate vasodilation include acetylcholine, epinephrine and nitric oxide. During vasodilation, the muscles lining a vessel relax, increasing the space inside the vessel and slowing the velocity of blood flow. Blood flow velocity is highest in the arterial system, while slowest in the capillaries and venules; constriction increases the velocity of blood flow, while dilation increases blood delivery to the tissues. A system of valves in the lower extremities are used to create a pressure gradient that directs deoxygenated blood back up to the inferior vena cava.

Answer 2

It doesn't. Read a book. It doesnt matter if you do this question or not because who needs school when you have SWAG.

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