The most important factor in the long-term regulation of ECF volume is
A)maintenance of salt balance
B)maintenance of water balance
C)thirst
D)the baroreceptor reflex
E)fluid shifts between the interstitial fluid and plasma

Question

Quizplus · Accepted Answer

The most important factor in the long-term regulation of ECF volume is maintenance of salt balance. This is because salt, specifically sodium, is the primary determinant of ECF volume. The kidneys play a crucial role in maintaining salt balance by regulating the reabsorption and excretion of sodium, which in turn affects the amount of water in the ECF. If there is an excess of sodium in the ECF, water will be retained, leading to an increase in ECF volume. Similarly, if there is a deficiency of sodium, water will be excreted, leading to a decrease in ECF volume. Thirst and the baroreceptor reflex are important short-term mechanisms for maintaining ECF volume, while fluid shifts between the interstitial fluid and plasma are more of a redistribution mechanism.

The Most Important Factor in the Long-Term Regulation of ECF