Answers 2026/2027 Galen College
Q1. Which body fluid compartment contains the greatest proportion
of total body water?
A) Extracellular fluid
B) Intracellular fluid
C) Plasma only
D) Transcellular fluid
Correct Answer: B) Intracellular fluid
Rationale: Intracellular fluid is the fluid contained within cells and
represents the largest body-fluid compartment.
Q2. Which electrolyte is the major cation in extracellular fluid?
A) Potassium
B) Magnesium
C) Sodium
D) Phosphate
Correct Answer: C) Sodium
Rationale: Sodium is the principal extracellular cation and plays a major
role in extracellular fluid volume and osmotic balance.
Q3. Which electrolyte is the major intracellular cation?
A) Potassium
B) Sodium
C) Calcium
D) Chloride
Correct Answer: A) Potassium
Rationale: Potassium is the predominant intracellular cation and is essential
for cellular membrane potentials and neuromuscular function.
Q4. Which hormone promotes water reabsorption by the kidneys?
A) Atrial natriuretic peptide
B) Antidiuretic hormone
C) Aldosterone
D) Insulin
, Correct Answer: B) Antidiuretic hormone
Rationale: Antidiuretic hormone increases renal water reabsorption,
reducing urine volume and helping maintain plasma osmolality.
Q5. Which hormone promotes sodium reabsorption and potassium
excretion by the kidneys?
A) Aldosterone
B) Antidiuretic hormone
C) Atrial natriuretic peptide
D) Insulin
Correct Answer: A) Aldosterone
Rationale: Aldosterone increases sodium reabsorption in the distal nephron
while promoting potassium secretion.
Q6. Which hormone promotes sodium and water excretion when
cardiac chambers are stretched by increased volume?
A) Cortisol
B) Aldosterone
C) Atrial natriuretic peptide
D) Antidiuretic hormone
Correct Answer: C) Atrial natriuretic peptide
Rationale: Atrial natriuretic peptide is released with atrial stretch and
promotes natriuresis and diuresis, helping reduce circulating volume.
Q7. Which process moves water across a selectively permeable
membrane toward the area with greater solute concentration?
A) Filtration
B) Diffusion
C) Osmosis
D) Active transport
Correct Answer: C) Osmosis
Rationale: Osmosis is the passive movement of water across a
semipermeable membrane toward the side with greater effective solute
concentration.
Q8. Which process requires cellular energy to move a substance
against its concentration gradient?