Which term refers to widening of the blood vessels that allows for increased blood flow?

Which term refers to widening of the blood vessels that allows for increased blood flow?

• A. Vasodilation
• B. Vasoconstriction
• C. Shock
• D. Hypotension

Answer: (A)

Widening of blood vessels that allows for increased blood flow is vasodilation. This happens when the smooth muscle in the walls of small arteries and arterioles relaxes, so the vessel radius increases. With a larger lumen, resistance drops and more blood can flow to tissues, improving delivery of oxygen and nutrients and aiding heat loss. Local factors (like high CO2, low O2, lactic acid, or inflammatory mediators) or signaling from the endothelium (such as nitric oxide) can trigger this relaxation, and it can be a targeted response in a specific tissue or occur systemically during activities like exercise or inflammation. Vasoconstriction, in contrast, narrows vessels and raises resistance, reducing flow. Shock is a condition involving inadequate perfusion that can involve various hemodynamic changes, and hypotension means abnormally low blood pressure—both outcomes or associated states rather than the term for widening.

Widening of blood vessels that allows for increased blood flow is vasodilation. This happens when the smooth muscle in the walls of small arteries and arterioles relaxes, so the vessel radius increases. With a larger lumen, resistance drops and more blood can flow to tissues, improving delivery of oxygen and nutrients and aiding heat loss. Local factors (like high CO2, low O2, lactic acid, or inflammatory mediators) or signaling from the endothelium (such as nitric oxide) can trigger this relaxation, and it can be a targeted response in a specific tissue or occur systemically during activities like exercise or inflammation.

Vasoconstriction, in contrast, narrows vessels and raises resistance, reducing flow. Shock is a condition involving inadequate perfusion that can involve various hemodynamic changes, and hypotension means abnormally low blood pressure—both outcomes or associated states rather than the term for widening.