Question 1

Which of the following best explains why water moves freely between the extracellular fluid (ECF) and intracellular fluid (ICF) compartments, but solute movement is more restricted?

Accepted Answer

Water moves by osmosis, which is driven by changes in ECF osmolality, whereas solute movement depends on size, charge, and transport proteins.

Question 2

A patient is admitted with severe dehydration. Which of the following is a likely consequence if water loss continues to exceed water intake?

Accepted Answer

Hypovolemic shock due to decreased blood volume

Question 3

Which hormone is primarily responsible for increasing water reabsorption in the renal collecting ducts, and what triggers its release?

Accepted Answer

Antidiuretic hormone (ADH); triggered by high ECF osmolality or low blood volume

Question 4

A patient with chronic vomiting is found to have a blood pH of 7.55 and elevated bicarbonate levels. Which acid-base disorder is most likely present?

Accepted Answer

Metabolic alkalosis

Question 5

Which of the following equations correctly represents the reversible equilibrium involved in the bicarbonate buffer system?

Accepted Answer

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

Question 6

Which of the following best describes the effect of aldosterone on sodium and potassium balance in the nephron?

Accepted Answer

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

Question 7

A patient with chronic obstructive pulmonary disease (COPD) has a blood pH of 7.30 and elevated $$\mathrm{P_{CO_2$}}. $$Which acid-base disorder is most likely present?

Accepted Answer

Respiratory acidosis

Question 8

Which of the following is a major difference between plasma and interstitial fluid composition?

Accepted Answer

Plasma contains more proteins than interstitial fluid.

Question 9

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

Accepted Answer

Atrial natriuretic peptide (ANP)

Question 10

A patient is experiencing muscle spasms and has a low blood calcium level. Which hormone is likely to be elevated in response?

Accepted Answer

Parathyroid hormone (PTH)

Question 11

Which of the following best explains why infants are more susceptible to dehydration and acidosis than adults?

Accepted Answer

Infants have a higher rate of fluid intake and output, higher metabolic rate, and immature kidneys.

Question 12

Which of the following is the primary mechanism by which the kidneys compensate for respiratory acidosis?

Accepted Answer

Increasing reabsorption and generation of bicarbonate in the plasma

Question 13

A patient with uncontrolled diabetes mellitus develops metabolic acidosis. Which of the following is a likely compensatory response?

Accepted Answer

Increased respiratory rate to eliminate CO$$_2$$

Question 14

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

Accepted Answer

They act rapidly to resist changes in pH by binding or releasing hydrogen ions.

Question 15

Which of the following is a consequence of hypotonic hydration?

Accepted Answer

Cells swell due to water influx, potentially causing cerebral edema.

Question 16

Which of the following best explains why sodium is the most important ion in determining ECF volume?

Accepted Answer

Sodium exerts the bulk of ECF osmotic pressure, controlling water movement.

Question 17

Which of the following best describes the effect of parathyroid hormone (PTH) on phosphate balance in the kidneys?

Accepted Answer

PTH decreases renal reabsorption of phosphate ions.

Question 18

A patient with severe diarrhea is losing large amounts of bicarbonate in the stool. Which acid-base disorder is most likely to develop?

Accepted Answer

Metabolic acidosis

Question 19

Which of the following is true regarding obligatory water loss?

Accepted Answer

It includes insensible water loss from the lungs, skin, feces, and a minimum urine output.

Question 20

Which of the following best describes the compensation for metabolic alkalosis?

Accepted Answer

The respiratory system decreases respiratory rate to retain CO$$_2$$ and lower pH.

Chapter 26: Fluids, Electrolytes, and Acid-Base Balance – Structured Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards