Describing a Physiological Variable as "Homeostatic" Means That It

Question

Describing a physiological variable as "homeostatic" means that it
A)has varied from the normal value,and will remain constant at the new value.
B)never varies from an exact set point value.
C)is in an equilibrium state that requires no energy input to stay at the normal value.
D)is in a state of dynamic constancy that is regulated to remain near a stable set point value.
E)has no normal range,but will just change to match the outside environmental conditions.

Accepted Answer

Describing a physiological variable as "homeostatic" means that it is in a state of dynamic constancy that is regulated to remain near a stable set point value. Homeostasis requires energy input but the variable remains within a narrow range to maintain the normal body function. Option A is incorrect because homeostasis requires energy input to maintain the normal value. Option B is incorrect because physiological variables have a range within which they can be considered normal. Option C is incorrect as a physiological variable in a state of homeostasis requires energy to stay at the normal value. Option E is incorrect because physiological variables have a normal range and are not simply influenced by the outside environment.