Vasodilation refers to which process?

Vasodilation refers to which process?

• A. Narrowing of blood vessels
• B. Widening of blood vessels
• C. Increased blood viscosity
• D. Constriction of arterioles

Answer: (B)

Vasodilation refers to widening of blood vessels. This happens when the smooth muscle in the vessel walls relaxes, increasing the diameter of the vessel. With a larger diameter, vascular resistance drops and more blood can flow to tissues, which helps deliver oxygen and nutrients or release heat as needed. This process is commonly driven by signals such as nitric oxide or reduced sympathetic activity. The other options describe different ideas: narrowing of vessels would be vasoconstriction, which restricts flow; increased blood viscosity means the blood is thicker, not that the vessels are widening; and constriction of arterioles is a specific form of vasoconstriction, not vasodilation.

Vasodilation refers to widening of blood vessels. This happens when the smooth muscle in the vessel walls relaxes, increasing the diameter of the vessel. With a larger diameter, vascular resistance drops and more blood can flow to tissues, which helps deliver oxygen and nutrients or release heat as needed. This process is commonly driven by signals such as nitric oxide or reduced sympathetic activity. The other options describe different ideas: narrowing of vessels would be vasoconstriction, which restricts flow; increased blood viscosity means the blood is thicker, not that the vessels are widening; and constriction of arterioles is a specific form of vasoconstriction, not vasodilation.