NURS 231 Pathophysiology – Portage Learning
2026/2027 Study Guide, Module Exam & Final
Exam Prep, Pathophysiology Review, Cellular
Injury, Immunity, Genetics, Fluid &
Electrolytes, Cardiovascular, Respiratory,
Renal, Neurologic Disorders, Practice
Questions & Detailed Rationales
Question 1: A 72-year-old male with a history of hypertension presents with a
sudden onset of severe, tearing chest pain radiating to his back. His blood
pressure is 180/110 mmHg in his right arm and 100/70 mmHg in his left arm.
Which of the following pathophysiological processes is most likely responsible
for this presentation?
A. Rupture of an atherosclerotic plaque in the coronary artery
B. Dissection of the tunica intima from the tunica media of the aorta
C. Acute inflammation of the pericardial sac
D. Spasm of the esophageal smooth muscle
CORRECT ANSWER: B. Dissection of the tunica intima from the tunica media
of the aorta
Rationale: The classic presentation of an aortic dissection includes sudden, severe
"tearing" chest pain that radiates to the back, often with a differential in blood pressure
between arms. This occurs when a tear in the tunica intima allows blood to enter the
tunica media, separating the layers of the aortic wall.
Question 2: A patient with chronic obstructive pulmonary disease (COPD) has
an arterial blood gas (ABG) showing pH 7.31, PaCO2 68 mmHg, and HCO3- 32
mEq/L. What is the primary acid-base disturbance, and what compensatory
mechanism is occurring?
A. Metabolic acidosis with respiratory compensation
B. Metabolic alkalosis with respiratory compensation
C. Respiratory acidosis with renal compensation
D. Respiratory alkalosis with renal compensation
CORRECT ANSWER: C. Respiratory acidosis with renal compensation
Rationale: The ABG shows a low pH (acidemia), elevated PaCO2 (respiratory acidosis),
and an elevated HCO3- (indicating metabolic compensation). In COPD, chronic
hypercapnia leads to renal retention of bicarbonate to buffer the acidosis. This is a
classic respiratory acidosis with metabolic compensation.
,Question 3: In a patient with type 1 diabetes mellitus, diabetic ketoacidosis
(DKA) is characterized by which of the following metabolic and electrolyte
imbalances?
A. Hyperglycemia, metabolic alkalosis, and hyperkalemia
B. Hyperglycemia, metabolic acidosis, and hyperkalemia
C. Hyperglycemia, metabolic acidosis, and hypokalemia
D. Hypoglycemia, metabolic acidosis, and hyperkalemia
CORRECT ANSWER: C. Hyperglycemia, metabolic acidosis, and hypokalemia
Rationale: DKA is defined by hyperglycemia, metabolic acidosis (due to ketone bodies),
and total body potassium depletion despite a normal or high serum potassium at
presentation. However, once insulin is administered, potassium shifts into cells,
revealing severe hypokalemia. Thus, C is correct as the pathophysiological state.
Question 4: A patient presents with jaundice, dark urine, and pale stools.
Laboratory tests reveal elevated unconjugated bilirubin and normal liver
enzymes. Which of the following is the most likely underlying mechanism?
A. Intrahepatic cholestasis
B. Hemolytic anemia
C. Biliary obstruction
D. Hepatocellular necrosis
CORRECT ANSWER: B. Hemolytic anemia
Rationale: Hemolytic anemia leads to excessive production of unconjugated (indirect)
bilirubin from the breakdown of red blood cells. The liver is unable to conjugate the
excess bilirubin, leading to increased unconjugated bilirubin in the blood. Since bilirubin
is not conjugated, it is not excreted into the bile, so stools remain normal-colored, not
pale. Dark urine is from urobilinogen, not conjugated bilirubin. Pale stools typically
indicate obstruction, which presents with elevated conjugated bilirubin.
Question 5: A patient with chronic heart failure is prescribed furosemide. This
medication reduces preload primarily through which of the following
mechanisms?
A. Increasing cardiac contractility
B. Decreasing systemic vascular resistance
C. Reducing circulating blood volume
D. Blocking beta-1 adrenergic receptors
CORRECT ANSWER: C. Reducing circulating blood volume
Rationale: Furosemide is a loop diuretic that inhibits the Na-K-2Cl cotransporter in the
ascending loop of Henle, leading to significant diuresis. This reduces total blood volume,
,which in turn decreases venous return to the heart (preload). Reducing preload is a key
therapeutic goal in managing heart failure.
Question 6: A 65-year-old patient is diagnosed with left-sided heart failure.
Which of the following clinical findings is most directly caused by the resultant
increase in pulmonary capillary hydrostatic pressure?
A. Jugular venous distention
B. Peripheral edema in the lower extremities
C. Pulmonary crackles and dyspnea
D. Hepatosplenomegaly
CORRECT ANSWER: C. Pulmonary crackles and dyspnea
Rationale: Left-sided heart failure leads to an inability of the left ventricle to pump blood
forward, causing blood to back up into the pulmonary circulation. This increases
pulmonary capillary hydrostatic pressure, forcing fluid into the interstitial spaces and
alveoli of the lungs, resulting in pulmonary edema, which presents as crackles and
dyspnea.
Question 7: During an acute asthma exacerbation, which of the following
pathophysiological changes is primarily responsible for the characteristic
wheezing sound?
A. Edema of the vocal cords
B. Narrowing of the airways due to bronchospasm, inflammation, and mucus
C. Collapse of the alveoli
D. Fluid accumulation in the pleural space
CORRECT ANSWER: B. Narrowing of the airways due to bronchospasm,
inflammation, and mucus
Rationale: Wheezing is a high-pitched, musical sound produced by air flowing through
narrowed airways. In asthma, airway narrowing is caused by a combination of
bronchospasm (smooth muscle constriction), mucosal inflammation and edema, and
increased mucus secretion. This creates turbulent airflow, resulting in wheezing.
Question 8: A patient with liver cirrhosis develops ascites. Which of the
following pathophysiological mechanisms is the primary contributor to the
formation of ascitic fluid?
A. Increased capillary hydrostatic pressure in the splanchnic circulation
B. Decreased plasma oncotic pressure due to hypoalbuminemia
C. Hyperaldosteronism leading to sodium and water retention
D. All of the above
, CORRECT ANSWER: D. All of the above
Rationale: Ascites formation in cirrhosis is multifactorial. Portal hypertension increases
hydrostatic pressure in splanchnic capillaries (A). Impaired liver synthesis of albumin
reduces plasma oncotic pressure (B). Cirrhosis also leads to secondary
hyperaldosteronism due to decreased hepatic metabolism of aldosterone and decreased
effective arterial blood volume, causing sodium and water retention (C). All three
mechanisms contribute significantly.
Question 9: A patient's laboratory results show a serum sodium of 118 mEq/L
and a serum osmolality of 250 mOsm/kg. He is confused and lethargic. Which
of the following is the most appropriate initial treatment strategy to prevent
complications?
A. Administer 3% hypertonic saline rapidly to correct the sodium deficit immediately
B. Restrict free water intake and administer normal saline slowly
C. Administer 0.9% normal saline rapidly and monitor urine output
D. Administer desmopressin to promote water retention
CORRECT ANSWER: B. Restrict free water intake and administer normal saline
slowly
Rationale: The patient has severe hyponatremia with symptoms. The most appropriate
management is slow correction of the sodium level to avoid osmotic demyelination
syndrome. This is typically done by restricting free water and using normal saline or
hypertonic saline cautiously. Rapid correction is dangerous and should be avoided.
Desmopressin would worsen the condition.
Question 10: A patient with chronic kidney disease (CKD) has a serum
creatinine of 4.5 mg/dL, BUN of 80 mg/dL, and a GFR of 15 mL/min/1.73m².
According to the Kidney Disease Outcomes Quality Initiative (KDOQI), which
stage of CKD is this patient in?
A. Stage 3
B. Stage 4
C. Stage 5
D. Stage 2
CORRECT ANSWER: B. Stage 4
Rationale: The KDOQI classification stages chronic kidney disease based on GFR. Stage
3 is GFR 30-59 mL/min, Stage 4 is GFR 15-29 mL/min, and Stage 5 is GFR less than 15
mL/min. With a GFR of 15, this patient is at the threshold and is classified as Stage 4
(severe CKD) and is approaching end-stage renal disease.
2026/2027 Study Guide, Module Exam & Final
Exam Prep, Pathophysiology Review, Cellular
Injury, Immunity, Genetics, Fluid &
Electrolytes, Cardiovascular, Respiratory,
Renal, Neurologic Disorders, Practice
Questions & Detailed Rationales
Question 1: A 72-year-old male with a history of hypertension presents with a
sudden onset of severe, tearing chest pain radiating to his back. His blood
pressure is 180/110 mmHg in his right arm and 100/70 mmHg in his left arm.
Which of the following pathophysiological processes is most likely responsible
for this presentation?
A. Rupture of an atherosclerotic plaque in the coronary artery
B. Dissection of the tunica intima from the tunica media of the aorta
C. Acute inflammation of the pericardial sac
D. Spasm of the esophageal smooth muscle
CORRECT ANSWER: B. Dissection of the tunica intima from the tunica media
of the aorta
Rationale: The classic presentation of an aortic dissection includes sudden, severe
"tearing" chest pain that radiates to the back, often with a differential in blood pressure
between arms. This occurs when a tear in the tunica intima allows blood to enter the
tunica media, separating the layers of the aortic wall.
Question 2: A patient with chronic obstructive pulmonary disease (COPD) has
an arterial blood gas (ABG) showing pH 7.31, PaCO2 68 mmHg, and HCO3- 32
mEq/L. What is the primary acid-base disturbance, and what compensatory
mechanism is occurring?
A. Metabolic acidosis with respiratory compensation
B. Metabolic alkalosis with respiratory compensation
C. Respiratory acidosis with renal compensation
D. Respiratory alkalosis with renal compensation
CORRECT ANSWER: C. Respiratory acidosis with renal compensation
Rationale: The ABG shows a low pH (acidemia), elevated PaCO2 (respiratory acidosis),
and an elevated HCO3- (indicating metabolic compensation). In COPD, chronic
hypercapnia leads to renal retention of bicarbonate to buffer the acidosis. This is a
classic respiratory acidosis with metabolic compensation.
,Question 3: In a patient with type 1 diabetes mellitus, diabetic ketoacidosis
(DKA) is characterized by which of the following metabolic and electrolyte
imbalances?
A. Hyperglycemia, metabolic alkalosis, and hyperkalemia
B. Hyperglycemia, metabolic acidosis, and hyperkalemia
C. Hyperglycemia, metabolic acidosis, and hypokalemia
D. Hypoglycemia, metabolic acidosis, and hyperkalemia
CORRECT ANSWER: C. Hyperglycemia, metabolic acidosis, and hypokalemia
Rationale: DKA is defined by hyperglycemia, metabolic acidosis (due to ketone bodies),
and total body potassium depletion despite a normal or high serum potassium at
presentation. However, once insulin is administered, potassium shifts into cells,
revealing severe hypokalemia. Thus, C is correct as the pathophysiological state.
Question 4: A patient presents with jaundice, dark urine, and pale stools.
Laboratory tests reveal elevated unconjugated bilirubin and normal liver
enzymes. Which of the following is the most likely underlying mechanism?
A. Intrahepatic cholestasis
B. Hemolytic anemia
C. Biliary obstruction
D. Hepatocellular necrosis
CORRECT ANSWER: B. Hemolytic anemia
Rationale: Hemolytic anemia leads to excessive production of unconjugated (indirect)
bilirubin from the breakdown of red blood cells. The liver is unable to conjugate the
excess bilirubin, leading to increased unconjugated bilirubin in the blood. Since bilirubin
is not conjugated, it is not excreted into the bile, so stools remain normal-colored, not
pale. Dark urine is from urobilinogen, not conjugated bilirubin. Pale stools typically
indicate obstruction, which presents with elevated conjugated bilirubin.
Question 5: A patient with chronic heart failure is prescribed furosemide. This
medication reduces preload primarily through which of the following
mechanisms?
A. Increasing cardiac contractility
B. Decreasing systemic vascular resistance
C. Reducing circulating blood volume
D. Blocking beta-1 adrenergic receptors
CORRECT ANSWER: C. Reducing circulating blood volume
Rationale: Furosemide is a loop diuretic that inhibits the Na-K-2Cl cotransporter in the
ascending loop of Henle, leading to significant diuresis. This reduces total blood volume,
,which in turn decreases venous return to the heart (preload). Reducing preload is a key
therapeutic goal in managing heart failure.
Question 6: A 65-year-old patient is diagnosed with left-sided heart failure.
Which of the following clinical findings is most directly caused by the resultant
increase in pulmonary capillary hydrostatic pressure?
A. Jugular venous distention
B. Peripheral edema in the lower extremities
C. Pulmonary crackles and dyspnea
D. Hepatosplenomegaly
CORRECT ANSWER: C. Pulmonary crackles and dyspnea
Rationale: Left-sided heart failure leads to an inability of the left ventricle to pump blood
forward, causing blood to back up into the pulmonary circulation. This increases
pulmonary capillary hydrostatic pressure, forcing fluid into the interstitial spaces and
alveoli of the lungs, resulting in pulmonary edema, which presents as crackles and
dyspnea.
Question 7: During an acute asthma exacerbation, which of the following
pathophysiological changes is primarily responsible for the characteristic
wheezing sound?
A. Edema of the vocal cords
B. Narrowing of the airways due to bronchospasm, inflammation, and mucus
C. Collapse of the alveoli
D. Fluid accumulation in the pleural space
CORRECT ANSWER: B. Narrowing of the airways due to bronchospasm,
inflammation, and mucus
Rationale: Wheezing is a high-pitched, musical sound produced by air flowing through
narrowed airways. In asthma, airway narrowing is caused by a combination of
bronchospasm (smooth muscle constriction), mucosal inflammation and edema, and
increased mucus secretion. This creates turbulent airflow, resulting in wheezing.
Question 8: A patient with liver cirrhosis develops ascites. Which of the
following pathophysiological mechanisms is the primary contributor to the
formation of ascitic fluid?
A. Increased capillary hydrostatic pressure in the splanchnic circulation
B. Decreased plasma oncotic pressure due to hypoalbuminemia
C. Hyperaldosteronism leading to sodium and water retention
D. All of the above
, CORRECT ANSWER: D. All of the above
Rationale: Ascites formation in cirrhosis is multifactorial. Portal hypertension increases
hydrostatic pressure in splanchnic capillaries (A). Impaired liver synthesis of albumin
reduces plasma oncotic pressure (B). Cirrhosis also leads to secondary
hyperaldosteronism due to decreased hepatic metabolism of aldosterone and decreased
effective arterial blood volume, causing sodium and water retention (C). All three
mechanisms contribute significantly.
Question 9: A patient's laboratory results show a serum sodium of 118 mEq/L
and a serum osmolality of 250 mOsm/kg. He is confused and lethargic. Which
of the following is the most appropriate initial treatment strategy to prevent
complications?
A. Administer 3% hypertonic saline rapidly to correct the sodium deficit immediately
B. Restrict free water intake and administer normal saline slowly
C. Administer 0.9% normal saline rapidly and monitor urine output
D. Administer desmopressin to promote water retention
CORRECT ANSWER: B. Restrict free water intake and administer normal saline
slowly
Rationale: The patient has severe hyponatremia with symptoms. The most appropriate
management is slow correction of the sodium level to avoid osmotic demyelination
syndrome. This is typically done by restricting free water and using normal saline or
hypertonic saline cautiously. Rapid correction is dangerous and should be avoided.
Desmopressin would worsen the condition.
Question 10: A patient with chronic kidney disease (CKD) has a serum
creatinine of 4.5 mg/dL, BUN of 80 mg/dL, and a GFR of 15 mL/min/1.73m².
According to the Kidney Disease Outcomes Quality Initiative (KDOQI), which
stage of CKD is this patient in?
A. Stage 3
B. Stage 4
C. Stage 5
D. Stage 2
CORRECT ANSWER: B. Stage 4
Rationale: The KDOQI classification stages chronic kidney disease based on GFR. Stage
3 is GFR 30-59 mL/min, Stage 4 is GFR 15-29 mL/min, and Stage 5 is GFR less than 15
mL/min. With a GFR of 15, this patient is at the threshold and is classified as Stage 4
(severe CKD) and is approaching end-stage renal disease.
