Vasodilation is defined as

• A. Blood flow is restricted from the extremities and skin.
• B. Blood pressure increases in peripheral vessels.
• C. Blood flows into the large muscle groups providing oxygen to power flight and aid in escape.
• D. Blood vessels contract to limit movement.

Answer: (C)

Vasodilation means the widening of blood vessels, especially the small arteries and arterioles, which increases blood flow to tissues. When the body needs more oxygen and nutrients quickly—like during the fight-or-flight response—the vessels supplying active muscles relax and dilate, allowing more blood to reach those muscles to power movement and escape. The option that describes blood flowing into the large muscle groups to provide oxygen for flight and escape best matches this increased perfusion to active muscles. The other statements describe vasoconstriction (vessels narrowing to limit movement) or changes that aren’t the definition of dilation, so they don’t fit as the concept.