Advanced Physiology and Pathophysiology
2nd Edition Exam Study Guide 2026/2027 –
Comprehensive Exam-Style Practice Questions
with Verified Answers, Detailed Rationales &
Proven Test-Taking Strategies | Trusted &
Reliable
1. A patient with severe hypoxemia has a PaO₂ of 55 mmHg
despite receiving a high inspired oxygen concentration. Which
pathophysiologic mechanism most strongly explains persistent
hypoxemia that responds poorly to supplemental oxygen?
A. Diffusion limitation
B. Ventilation-perfusion mismatch
C. Right-to-left intrapulmonary shunt
D. Reduced inspired oxygen tension
Correct answer: C. Right-to-left intrapulmonary shunt
The rationale: In a true shunt, perfusion reaches alveoli that are
not ventilated, so deoxygenated blood enters the systemic
circulation without contacting ventilated alveoli. Increasing
inspired oxygen has limited ability to correct the resulting
hypoxemia. Ventilation-perfusion mismatch and diffusion
,limitation generally demonstrate a greater response to
supplemental oxygen.
2. A patient with chronic hypercapnia has a PaCO₂ of 58 mmHg
and an arterial pH of 7.37. Which renal adaptation is primarily
responsible for maintaining near-normal extracellular pH?
A. Increased bicarbonate excretion
B. Decreased hydrogen ion secretion
C. Increased bicarbonate reabsorption and generation
D. Decreased ammonium production
Correct answer: C. Increased bicarbonate reabsorption and
generation
The rationale: Chronic respiratory acidosis stimulates the
kidneys to increase hydrogen ion secretion, ammonium
excretion, and generation and retention of bicarbonate. This
renal compensation raises plasma bicarbonate and partially or
substantially corrects the pH. The compensation develops over
several days rather than immediately.
3. A patient develops severe dehydration after several days of
vomiting and diarrhea. Which physiologic change most directly
stimulates antidiuretic hormone secretion?
,A. Increased atrial natriuretic peptide release
B. Decreased plasma osmolality
C. Increased plasma osmolality and decreased effective
circulating volume
D. Increased renal perfusion
Correct answer: C. Increased plasma osmolality and decreased
effective circulating volume
The rationale: Antidiuretic hormone secretion is stimulated
strongly by increased plasma osmolality and, particularly when
substantial, by decreased effective circulating volume. ADH
increases water permeability in the collecting ducts through
insertion of aquaporin-2 channels, promoting water retention.
Atrial natriuretic peptide has an opposing effect on sodium and
volume retention.
4. Which change is most characteristic of left-sided heart failure
causing pulmonary edema?
A. Increased pulmonary capillary hydrostatic pressure
B. Decreased pulmonary venous pressure
C. Reduced pulmonary interstitial fluid formation
D. Increased plasma oncotic pressure
Correct answer: A. Increased pulmonary capillary hydrostatic
pressure
, The rationale: Left ventricular dysfunction raises left atrial and
pulmonary venous pressures, increasing pulmonary capillary
hydrostatic pressure. When this pressure exceeds the capacity
of lymphatic drainage, fluid moves into the pulmonary
interstitium and eventually the alveolar spaces. This is
hydrostatic pulmonary edema rather than edema primarily
caused by increased vascular permeability.
5. A patient with septic shock has warm extremities,
hypotension, tachycardia, and an elevated serum lactate
concentration. Which hemodynamic abnormality is most
characteristic of early distributive shock?
A. Markedly increased systemic vascular resistance
B. Decreased systemic vascular resistance
C. Increased left ventricular afterload
D. Reduced vascular capacitance with severe vasoconstriction
Correct answer: B. Decreased systemic vascular resistance
The rationale: Early distributive shock is characterized by
profound vasodilation, resulting in reduced systemic vascular
resistance and abnormal distribution of blood flow. Increased
vascular capacitance also contributes to reduced effective
circulating volume. Although cardiac output may initially be
preserved or elevated, tissue perfusion can remain inadequate.
2nd Edition Exam Study Guide 2026/2027 –
Comprehensive Exam-Style Practice Questions
with Verified Answers, Detailed Rationales &
Proven Test-Taking Strategies | Trusted &
Reliable
1. A patient with severe hypoxemia has a PaO₂ of 55 mmHg
despite receiving a high inspired oxygen concentration. Which
pathophysiologic mechanism most strongly explains persistent
hypoxemia that responds poorly to supplemental oxygen?
A. Diffusion limitation
B. Ventilation-perfusion mismatch
C. Right-to-left intrapulmonary shunt
D. Reduced inspired oxygen tension
Correct answer: C. Right-to-left intrapulmonary shunt
The rationale: In a true shunt, perfusion reaches alveoli that are
not ventilated, so deoxygenated blood enters the systemic
circulation without contacting ventilated alveoli. Increasing
inspired oxygen has limited ability to correct the resulting
hypoxemia. Ventilation-perfusion mismatch and diffusion
,limitation generally demonstrate a greater response to
supplemental oxygen.
2. A patient with chronic hypercapnia has a PaCO₂ of 58 mmHg
and an arterial pH of 7.37. Which renal adaptation is primarily
responsible for maintaining near-normal extracellular pH?
A. Increased bicarbonate excretion
B. Decreased hydrogen ion secretion
C. Increased bicarbonate reabsorption and generation
D. Decreased ammonium production
Correct answer: C. Increased bicarbonate reabsorption and
generation
The rationale: Chronic respiratory acidosis stimulates the
kidneys to increase hydrogen ion secretion, ammonium
excretion, and generation and retention of bicarbonate. This
renal compensation raises plasma bicarbonate and partially or
substantially corrects the pH. The compensation develops over
several days rather than immediately.
3. A patient develops severe dehydration after several days of
vomiting and diarrhea. Which physiologic change most directly
stimulates antidiuretic hormone secretion?
,A. Increased atrial natriuretic peptide release
B. Decreased plasma osmolality
C. Increased plasma osmolality and decreased effective
circulating volume
D. Increased renal perfusion
Correct answer: C. Increased plasma osmolality and decreased
effective circulating volume
The rationale: Antidiuretic hormone secretion is stimulated
strongly by increased plasma osmolality and, particularly when
substantial, by decreased effective circulating volume. ADH
increases water permeability in the collecting ducts through
insertion of aquaporin-2 channels, promoting water retention.
Atrial natriuretic peptide has an opposing effect on sodium and
volume retention.
4. Which change is most characteristic of left-sided heart failure
causing pulmonary edema?
A. Increased pulmonary capillary hydrostatic pressure
B. Decreased pulmonary venous pressure
C. Reduced pulmonary interstitial fluid formation
D. Increased plasma oncotic pressure
Correct answer: A. Increased pulmonary capillary hydrostatic
pressure
, The rationale: Left ventricular dysfunction raises left atrial and
pulmonary venous pressures, increasing pulmonary capillary
hydrostatic pressure. When this pressure exceeds the capacity
of lymphatic drainage, fluid moves into the pulmonary
interstitium and eventually the alveolar spaces. This is
hydrostatic pulmonary edema rather than edema primarily
caused by increased vascular permeability.
5. A patient with septic shock has warm extremities,
hypotension, tachycardia, and an elevated serum lactate
concentration. Which hemodynamic abnormality is most
characteristic of early distributive shock?
A. Markedly increased systemic vascular resistance
B. Decreased systemic vascular resistance
C. Increased left ventricular afterload
D. Reduced vascular capacitance with severe vasoconstriction
Correct answer: B. Decreased systemic vascular resistance
The rationale: Early distributive shock is characterized by
profound vasodilation, resulting in reduced systemic vascular
resistance and abnormal distribution of blood flow. Increased
vascular capacitance also contributes to reduced effective
circulating volume. Although cardiac output may initially be
preserved or elevated, tissue perfusion can remain inadequate.
