At rest, which statement about overall blood distribution is accurate?

• A. 90% of blood goes to active muscles
• B. Vasodilation directs more blood to the skin
• C. About 20% of blood is directed to all organs with skin receiving minimum flow
• D. Capillaries are fully dilated to maximize tissue perfusion

Answer: (C)

At rest, blood flow is prioritized to organs that maintain essential bodily functions, while less is sent to muscles and skin. The combined flow to all the visceral organs amounts to roughly about one-fifth of the cardiac output, and the skin receives relatively little blood flow. This makes the statement that about 20% of blood is directed to all organs with skin receiving minimum flow the best description of rest distribution. If the body needs to dissipate heat or support activity, blood flow to skin and skeletal muscle can increase, but at rest those beds are not the primary recipients. Capillaries are not all fully dilated at rest, and large-scale vasodilation of the skin to maximize tissue perfusion isn’t the prevailing state when the body is just resting.