Question 1

Which of the following best explains why infants have a higher percentage of body water compared to adults?

Accepted Answer

Infants have lower bone mass and lower fat content.

Question 2

A patient is experiencing severe burns and prolonged vomiting. Which fluid and electrolyte disorder is most likely to develop?

Accepted Answer

Dehydration

Question 3

Which compartment contains the largest volume of body water?

Accepted Answer

Intracellular fluid

Question 4

Which of the following is the major cation in the extracellular fluid (ECF)?

Accepted Answer

Na+

Question 5

A patient presents with swelling of the legs and low plasma protein levels due to liver disease. What is the most likely cause of the edema?

Accepted Answer

Decreased colloid osmotic pressure in the plasma

Question 6

Which hormone is released in response to increased blood pressure and causes increased excretion of sodium and water?

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 7

If a patient has a blood pH of 7.30, a PCO2 of 50 mm Hg, and an elevated HCO3^- level, which acid-base disorder and compensation are present?

Accepted Answer

Respiratory acidosis with renal compensation

Question 8

Which buffer system is the most important for buffering pH changes in the extracellular fluid (ECF)?

Accepted Answer

Bicarbonate buffer system

Question 9

A patient with chronic kidney disease is unable to excrete enough H+ ions. What acid-base imbalance is most likely to occur?

Accepted Answer

Metabolic acidosis

Question 10

Which of the following equations correctly represents the reversible equilibrium involved in respiratory regulation of H+?

Accepted Answer

$$ \mathrm{CO_2 + H_2O \rightleftharpoons H_2CO_3 \rightleftharpoons H^+ + HCO_3^-} $$

Question 11

A marathon runner collapses after a race and is found to have low blood pH, low HCO3^-, and low PCO2. What is the most likely diagnosis?

Accepted Answer

Metabolic acidosis with respiratory compensation

Question 12

Which of the following best describes the effect of aldosterone on renal function?

Accepted Answer

It increases sodium reabsorption and potassium secretion in the distal nephron.

Question 13

Which of the following is a consequence of hypotonic hydration (water intoxication)?

Accepted Answer

Cells swell due to water gain

Question 14

Which hormone increases calcium reabsorption in the kidneys and stimulates osteoclast activity in bone?

Accepted Answer

Parathyroid hormone (PTH)

Question 15

A patient is taking large amounts of antacids and presents with slow, shallow breathing and elevated blood HCO3^-. What is the most likely acid-base disorder?

Accepted Answer

Metabolic alkalosis with respiratory compensation

Question 16

Which of the following best explains why hyperkalemia can lead to cardiac arrhythmias?

Accepted Answer

It increases the resting membrane potential, making cells more excitable.

Question 17

Which of the following is true regarding the phosphate buffer system?

Accepted Answer

It is effective in urine and intracellular fluid where phosphate concentrations are high.

Question 18

Which process is responsible for the obligatory water loss in urine each day?

Accepted Answer

Excretion of metabolic wastes

Question 19

Which of the following best describes the effect of acidosis on potassium distribution between the intracellular and extracellular compartments?

Accepted Answer

Acidosis shifts K+ out of cells

Question 20

Which of the following best describes the role of the kidneys in acid-base balance?

Accepted Answer

They excrete fixed metabolic acids and generate new bicarbonate ions.

Fluid, Electrolyte, and Acid-Base Balance: Study Notes for Anatomy & Physiology

Study Guide - Practice Questions

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