Sodium depletion differs from water depletion in that
A. Cardiovascular changes are less pronounced.
B. Intracellular fluid volume is less affected.
C. The haematocrit increases.
D. Thirst is more severe.
E. Antidiuretic hormone levels are higher.
The correct answer is:
B. Intracellular fluid volume is less affected.
Sodium depletion (hyponatremia) primarily affects the extracellular fluid compartment, whereas water depletion (dehydration) affects both intracellular and extracellular compartments.
In sodium depletion:
– Intracellular fluid volume is relatively preserved
– Extracellular fluid volume is decreased, leading to decreased blood volume and pressure