Which of the following describes a primary physiological response to cold application?

Which of the following describes a primary physiological response to cold application?

• A. Vasodilation and increased vascular permeability.
• B. Vasoconstriction and decreased vascular permeability, reducing cell metabolism, inflammation, circulation, pain perception, and muscle spasm.
• C. Increased blood flow to the area.
• D. Increased tissue metabolism.

Answer: (B)

When cold is applied, the body’s immediate response is vasoconstriction—blood vessels in the area narrow—and a reduction in capillary permeability. This limits fluid leakage and edema. The cooler temperature also lowers tissue metabolism, which helps slow inflammatory processes and further reduces metabolic demand. With less circulation to the area, pain perception diminishes because nerve conduction slows and the area becomes less reactive. Muscle spasm is reduced as inflammation decreases and reflex muscle activity is dampened. This combination of vasoconstriction, decreased permeability, reduced metabolism, and diminished pain and spasm is precisely described in the statement. The other ideas describe responses more typical of heat application or no change: vasodilation would increase blood flow and permeability; increased blood flow contradicts the cooling effect; and increased tissue metabolism would occur with warming, not cooling.

When cold is applied, the body’s immediate response is vasoconstriction—blood vessels in the area narrow—and a reduction in capillary permeability. This limits fluid leakage and edema. The cooler temperature also lowers tissue metabolism, which helps slow inflammatory processes and further reduces metabolic demand. With less circulation to the area, pain perception diminishes because nerve conduction slows and the area becomes less reactive. Muscle spasm is reduced as inflammation decreases and reflex muscle activity is dampened. This combination of vasoconstriction, decreased permeability, reduced metabolism, and diminished pain and spasm is precisely described in the statement.

The other ideas describe responses more typical of heat application or no change: vasodilation would increase blood flow and permeability; increased blood flow contradicts the cooling effect; and increased tissue metabolism would occur with warming, not cooling.