NUR 242 Med Surg Exam 3 – Complete Test Bank with Verified Answers & Rationales (2025/2026)
Welcome to your comprehensive study guide for the NUR 242 Medical-Surgical Nursing Exam 3. This
guide is compiled from verified 2025-2026 exam materials and covers the core topics of respiratory
disorders, fluid and electrolyte balance, and renal disorders .
Exam Overview & Key Topics
The NUR 242 Exam 3 covers advanced medical-surgical nursing concepts, with a focus on the following
areas :
Topic Area Key Concepts
Ventilation/perfusion, chemoreceptors, lung mechanics, asthma, COPD, pneumonia, TB, ARDS,
Respiratory
pneumothorax, pleural effusion, lung cancer
Fluid & Fluid compartments, osmosis, tonicity, edema, dehydration, sodium/potassium/calcium disorders,
Electrolytes interpretation
GFR, BUN/creatinine ratio, pyelonephritis, glomerulonephritis, nephrotic syndrome, AKI (phases),
Renal
chronic renal failure, UTIs
SECTION 1: RESPIRATORY PHYSIOLOGY & MECHANICS
Q1. What is ventilation?
• A) The circulation of blood through the lungs
• B) The movement of air into and out of the lungs
• C) The exchange of gases in the alveoli
• D) The transport of oxygen by hemoglobin
✅ Answer: B
Rationale: Ventilation is the mechanical process of moving air into and out of the lungs. Perfusion is the
circulation of blood through the lungs .
Q2. What are central chemoreceptors responsive to?
• A) Decreased PaO2
• B) Increased H+ in the brain ECF and increased PaCO2
• C) Decreased pH only
, • D) Increased PaO2
✅ Answer: B
Rationale: Central chemoreceptors are primarily responsive to increased H+ in the brain extracellular
fluid and increased PaCO2, which is known as the "hypercarbic drive." Peripheral chemoreceptors
respond to decreased pH, increased PaCO2, and decreased PaO2 ("hypoxic drive") .
Q3. What is the function of surfactant?
• A) To increase surface tension in the alveoli
• B) To stabilize the alveoli and keep them dry
• C) To decrease lung compliance
• D) To increase airway resistance
✅ Answer: B
Rationale: Surfactant is a complex substance lining the alveoli that reduces surface tension throughout
the lungs, contributing to lung compliance. It stabilizes the alveoli and keeps them dry. It is produced by
Type II alveolar cells .
Q4. According to Poiseuille's law, what happens if the radius of an airway decreases?
• A) Resistance decreases
• B) Resistance increases
• C) Resistance remains unchanged
• D) Resistance becomes zero
✅ Answer: B
Rationale: Poiseuille's law states that resistance = (8 × viscosity × length) / (π × radius^4). This means
that resistance is inversely proportional to the fourth power of the radius, so even a small decrease in
radius results in a significant increase in resistance .
Q5. Which condition causes a right shift in the oxygen-hemoglobin dissociation curve (decreased
affinity)?
• A) Alkalemia
• B) Hypothermia
• C) Acidemia and hyperthermia
• D) Hypocarbia
✅ Answer: C
Rationale: A right shift in the oxyhemoglobin dissociation curve indicates decreased affinity of
hemoglobin for oxygen, meaning oxygen is more readily released to tissues. This is caused by acidemia
Welcome to your comprehensive study guide for the NUR 242 Medical-Surgical Nursing Exam 3. This
guide is compiled from verified 2025-2026 exam materials and covers the core topics of respiratory
disorders, fluid and electrolyte balance, and renal disorders .
Exam Overview & Key Topics
The NUR 242 Exam 3 covers advanced medical-surgical nursing concepts, with a focus on the following
areas :
Topic Area Key Concepts
Ventilation/perfusion, chemoreceptors, lung mechanics, asthma, COPD, pneumonia, TB, ARDS,
Respiratory
pneumothorax, pleural effusion, lung cancer
Fluid & Fluid compartments, osmosis, tonicity, edema, dehydration, sodium/potassium/calcium disorders,
Electrolytes interpretation
GFR, BUN/creatinine ratio, pyelonephritis, glomerulonephritis, nephrotic syndrome, AKI (phases),
Renal
chronic renal failure, UTIs
SECTION 1: RESPIRATORY PHYSIOLOGY & MECHANICS
Q1. What is ventilation?
• A) The circulation of blood through the lungs
• B) The movement of air into and out of the lungs
• C) The exchange of gases in the alveoli
• D) The transport of oxygen by hemoglobin
✅ Answer: B
Rationale: Ventilation is the mechanical process of moving air into and out of the lungs. Perfusion is the
circulation of blood through the lungs .
Q2. What are central chemoreceptors responsive to?
• A) Decreased PaO2
• B) Increased H+ in the brain ECF and increased PaCO2
• C) Decreased pH only
, • D) Increased PaO2
✅ Answer: B
Rationale: Central chemoreceptors are primarily responsive to increased H+ in the brain extracellular
fluid and increased PaCO2, which is known as the "hypercarbic drive." Peripheral chemoreceptors
respond to decreased pH, increased PaCO2, and decreased PaO2 ("hypoxic drive") .
Q3. What is the function of surfactant?
• A) To increase surface tension in the alveoli
• B) To stabilize the alveoli and keep them dry
• C) To decrease lung compliance
• D) To increase airway resistance
✅ Answer: B
Rationale: Surfactant is a complex substance lining the alveoli that reduces surface tension throughout
the lungs, contributing to lung compliance. It stabilizes the alveoli and keeps them dry. It is produced by
Type II alveolar cells .
Q4. According to Poiseuille's law, what happens if the radius of an airway decreases?
• A) Resistance decreases
• B) Resistance increases
• C) Resistance remains unchanged
• D) Resistance becomes zero
✅ Answer: B
Rationale: Poiseuille's law states that resistance = (8 × viscosity × length) / (π × radius^4). This means
that resistance is inversely proportional to the fourth power of the radius, so even a small decrease in
radius results in a significant increase in resistance .
Q5. Which condition causes a right shift in the oxygen-hemoglobin dissociation curve (decreased
affinity)?
• A) Alkalemia
• B) Hypothermia
• C) Acidemia and hyperthermia
• D) Hypocarbia
✅ Answer: C
Rationale: A right shift in the oxyhemoglobin dissociation curve indicates decreased affinity of
hemoglobin for oxygen, meaning oxygen is more readily released to tissues. This is caused by acidemia
