6.7: Chapter Review Questions

Multiple Choice Section

• Use the end‑of‑chapter multiple‑choice section as a regular self‑check tool, not just before exams.
• Read each item carefully, think about what is really being tested (concept, definition, application, or calculation), and choose the option (A, B, C, or D) that best reflects what you have learned in this chapter.
  • After you read through the chapter, attempt all items without looking at your notes; then return to the chapter to review any you missed or felt unsure about.
  • Afterward, explain to yourself why the correct option is right and why the others are not. Finally, repeat the multiple‑choice section a few days later to see what you truly remember and understand.
• Students who consistently use these prompts in this way typically perform better across the course because they turn reading into active practice

1. A patient receiving IV fluids develops swelling of tissues as water moves out of cells into the interstitial space, following a change in solute concentration. Solutes contribute to the movement of water between cells and the surrounding medium primarily by creating:
   A. Osmotic pressure
   B. Hydrostatic pressure
   C. Brownian movement
   D. Random motion

2. A lab report shows an ion with a net positive electrical charge. This ion is referred to as a:
   A. Neutral particle
   B. Cation
   C. Alternating ion
   D. Anion

3. A researcher is sampling different body fluid compartments. Interstitial fluid (IF) is best described as:
   A. The fluid in the cytosol of the cells
   B. The fluid component of blood (plasma)
   C. The fluid that bathes all of the body’s cells except for blood cells
   D. The intracellular fluids found between organelle membranes

4. A dietitian is teaching a patient about fluid balance. On an average day, the largest amount of water enters the body via:
   A. Metabolic water production
   B. Water content of solid foods
   C. Ingested liquids
   D. Humidified air

5. A person with normal kidney function records fluid intake and output over 24 hours. The largest amount of water typically leaves the body via:
   A. Feces from the GI tract
   B. The skin as sweat
   C. Water vapor in expired air
   D. Urine

6. A nurse explains to a patient that some daily water loss occurs even when they are not aware of it. Insensible water loss refers to water lost via:
   A. Skin evaporation and exhaled air from the lungs
   B. Urine
   C. Excessive sweating during exercise
   D. Vomiting or diarrhea

7. A healthy adult drinks a large glass of water. Studies on renal physiology show that the kidneys respond relatively quickly to this intake. On average, how soon after drinking will a measurable increase in urine output begin?
   A. 5 minutes
   B. 30 minutes
   C. 1 hour
   D. 3 hours

8. A patient with osteoporosis is told that bone acts as a mineral reservoir for certain ions important in nerve conduction and energy metabolism. Bone serves as a mineral reserve primarily for which two ions?
   A. Sodium and potassium
   B. Calcium and phosphate
   C. Chloride and bicarbonate
   D. Calcium and bicarbonate

9. A marathon runner is told to replace not only water but also electrolytes lost in sweat. Over the course of a typical day, most electrolytes are lost from the body through:
   A. Renal function (urine)
   B. Sweating
   C. Feces
   D. Respiration

10. A basic metabolic panel shows normal extracellular ion levels. The major cation in extracellular fluid (such as plasma and interstitial fluid) is:
    A. Sodium
    B. Potassium
    C. Chloride
    D. Bicarbonate

11. An intracellular fluid sample from skeletal muscle cells is analyzed. The major cation in intracellular fluid is:
    A. Sodium
    B. Potassium
    C. Chloride
    D. Bicarbonate

12. A physician explains to a patient that an imbalance of a major anion in the extracellular fluid can affect nerve and muscle function. The major anion in extracellular fluid is:
    A. Sodium
    B. Potassium
    C. Chloride
    D. Bicarbonate

13. A 70-year-old woman is evaluated for osteoporosis. A bone density scan shows reduced mineral content. Most of the body’s calcium is found in:
    A. Teeth only
    B. Bone
    C. Plasma
    D. Extracellular fluids outside the skeleton

14. A dehydrated patient receiving hypertonic saline develops neurologic symptoms. Laboratory tests reveal abnormally high blood sodium levels. Abnormally increased blood levels of sodium are termed:
    A. Hyperkalemia
    B. Hyperchloremia
    C. Hypernatremia
    D. Hypercalcemia

15. A laboratory report compares typical plasma concentrations of major ions. Which of the following ions normally has the lowest concentration in blood plasma?
    A. Sodium
    B. Potassium
    C. Chloride
    D. Bicarbonate

16. A patient with adrenal gland dysfunction has abnormal levels of a hormone that alters kidney handling of certain ions. Which two ions are most directly affected by aldosterone in the kidneys?
    A. Sodium and potassium
    B. Chloride and bicarbonate
    C. Calcium and phosphate
    D. Sodium and phosphate

17. A physiologist is studying buffering systems in red blood cells (RBCs). Inside RBCs, which of the following is the most important buffer that helps maintain intracellular pH?
    A. Plasma proteins
    B. Hemoglobin
    C. Phosphate buffers
    D. Bicarbonate–carbonic acid buffer

18. A professor explains how proteins help maintain blood pH. Which explanation best describes why plasma proteins can function as buffers?
    A. Plasma proteins combine with bicarbonate to form a stronger buffer
    B. Plasma proteins are not affected by acids
    C. Proteins have both positive and negative charges on their surfaces that can bind H⁺
    D. Proteins are strongly alkaline at all times

19. The main buffer system that is actively regulated to control the body’s overall acid–base balance is the:
    A. Plasma protein buffer system
    B. Hemoglobin buffer system
    C. Phosphate buffer system
    D. Bicarbonate–carbonic acid buffer system

20. A patient with chronic lung disease has altered levels of carbon dioxide and carbonic acid. Carbonic acid (H₂CO₃) levels in the blood are primarily controlled through the:
    A. Respiratory system
    B. Renal system
    C. Digestive system
    D. Metabolic rate of cells

21. A patient with chronic kidney disease has difficulty regulating bicarbonate (HCO₃⁻) levels in the blood. Bicarbonate ion concentrations in the blood are primarily controlled through the:
    A. Respiratory system
    B. Renal system
    C. Digestive system
    D. Metabolic rate of cells

22. Red blood cells contain the enzyme carbonic anhydrase, which helps rapidly interconvert carbon dioxide and water with carbonic acid and bicarbonate. Which reaction is catalyzed by carbonic anhydrase?
    A. CO₂ + H₂O ⇌ H₂CO₃ ⇌ H⁺ + HCO₃⁻
    B. HCl + HCO₃⁻ ⇌ H₂CO₃ + Cl⁻
    C. NaHCO₃ ⇌ Na⁺ + HCO₃⁻
    D. H₂CO₃ ⇌ CO₂ + ½O₂

23. A patient with severe diarrhea loses large amounts of bicarbonate-rich intestinal fluid and presents with low blood pH. Which of the following is a common cause of metabolic acidosis?
    A. Excessive loss of gastric HCl from vomiting
    B. Increased aldosterone
    C. Diarrhea
    D. Prolonged use of loop diuretics

24. A 65-year-old man with long-term emphysema has chronic CO₂ retention and low blood pH. Which of the following is a typical cause of respiratory acidosis?
    A. Emphysema with hypoventilation
    B. Low blood potassium (hypokalemia)
    C. Increased aldosterone secretion
    D. Increased blood ketones in diabetes

25. In an arterial blood gas from a healthy adult, pH is 7.40 and the bicarbonate–carbonic acid buffer system is in its normal ratio. At a pH of 7.40, the HCO₃⁻ to H₂CO₃ (bicarbonate to carbonic acid) ratio is approximately:
    A. 35:1
    B. 4:1
    C. 20:1
    D. 3:1