WCU Pathophysiology Midterm Exam – 100% Verified
Practice Questions and Rationalized Correct Answers
Question 1: Which of the following is the primary cause of cellular injury in hypoxia?
a. Increased oxidative phosphorylation
b. Depletion of ATP
c. Excessive calcium influx
d. Mitochondrial hyperplasia
Correct Answer: B. Depletion of ATP
Explanation: Hypoxia leads to insufficient oxygen supply, impairing aerobic metabolism
and reducing ATP production. ATP depletion disrupts cellular processes, includ-
ing ion pumps, causing cellular injury. Increased oxidative phosphorylation (A)
requires oxygen, excessive calcium influx (C) is a secondary effect, and mitochon-
drial hyperplasia (D) is not a direct consequence of hypoxia.
Question 2: What is the hallmark feature of apoptosis?
a. Cellular swelling
b. Chromatin condensation
c. Membrane rupture
d. Inflammatory response
Correct Answer: B. Chromatin condensation
Explanation: Apoptosis is programmed cell death characterized by chromatin
condensation, DNA fragmentation, and cell shrinkage without inflammation. Cel-
lular swelling (A) and membrane rupture (C) occur in necrosis, and apoptosis
typically does not trigger an inflammatory response (D).
Question 3: Which electrolyte imbalance is most commonly associated with cardiac arrhyth-
mias?
a. Hypernatremia
b. Hypokalemia
c. Hypermagnesemia
d. Hypocalcemia
Correct Answer: B. Hypokalemia
Explanation: Hypokalemia lowers potassium levels, altering membrane poten-
tials and predisposing to cardiac arrhythmias. Hypernatremia (A) affects fluid
balance, hypermagnesemia (C) may cause bradycardia, and hypocalcemia (D)
can lead to tetany but is less directly linked to arrhythmias.
Question 4: In which condition is Kussmaul breathing most likely observed?
a. Metabolic acidosis
1
, b. Respiratory alkalosis
c. Chronic obstructive pulmonary disease
d. Pulmonary edema
Correct Answer: A. Metabolic acidosis
Explanation: Kussmaul breathing is a compensatory hyperventilation seen in
metabolic acidosis to eliminate excess carbon dioxide and reduce acidity. Respi-
ratory alkalosis (B) involves hypoventilation, COPD (C) causes hypoventilation,
and pulmonary edema (D) leads to labored breathing but not typically Kussmaul’s
pattern.
Question 5: What is the primary source of energy for erythrocytes?
a. Oxidative phosphorylation
b. Glycolysis
c. Krebs cycle
d. Beta-oxidation
Correct Answer: B. Glycolysis
Explanation: Erythrocytes lack mitochondria, relying on anaerobic glycolysis
for ATP production. Oxidative phosphorylation (A) and the Krebs cycle (C) re-
quire mitochondria, and beta-oxidation (D) occurs in other cell types for fatty acid
metabolism.
Question 6: Which type of necrosis is most commonly associated with tuberculosis?
a. Coagulative
b. Liquefactive
c. Caseous
d. Fat
Correct Answer: C. Caseous
Explanation: Caseous necrosis, characterized by a cheese-like appearance, is
typical in tuberculosis due to granulomatous inflammation. Coagulative necrosis
(A) occurs in ischemic tissues, liquefactive necrosis (B) in bacterial infections or
brain tissue, and fat necrosis (D) in pancreatic or breast tissue injury.
Question 7: What is the primary pathophysiological mechanism of type 1 diabetes mellitus?
a. Insulin resistance
b. Autoimmune destruction of beta cells
c. Increased glucagon secretion
d. Impaired glucose uptake
Correct Answer: B. Autoimmune destruction of beta cells
Explanation: Type 1 diabetes results from autoimmune destruction of pancreatic
beta cells, leading to insulin deficiency. Insulin resistance (A) is characteristic
2
, of type 2 diabetes, increased glucagon secretion (C) is secondary, and impaired
glucose uptake (D) is a consequence, not the primary mechanism.
Question 8: Which of the following is a characteristic feature of chronic inflammation?
a. Neutrophil predominance
b. Tissue necrosis
c. Mononuclear cell infiltration
d. Exudate formation
Correct Answer: C. Mononuclear cell infiltration
Explanation: Chronic inflammation is marked by infiltration of mononuclear cells
(lymphocytes, macrophages). Neutrophils (A) predominate in acute inflammation,
tissue necrosis (B) is not always present, and exudate formation (D) is more typical
of acute inflammation.
Question 9: What is the most common cause of metabolic alkalosis?
a. Hyperventilation
b. Vomiting
c. Diarrhea
d. Renal failure
Correct Answer: B. Vomiting
Explanation: Vomiting causes loss of gastric acid, leading to metabolic alkalosis.
Hyperventilation (A) causes respiratory alkalosis, diarrhea (C) leads to metabolic
acidosis, and renal failure (D) typically causes metabolic acidosis due to impaired
acid excretion.
Question 10: Which cytokine is primarily responsible for the fever response in inflammation?
a. IL-2
b. TNF-alpha
c. IL-6
d. IL-10
Correct Answer: C. IL-6
Explanation: IL-6 stimulates the hypothalamus to increase body temperature dur-
ing inflammation. IL-2 (A) promotes T-cell proliferation, TNF-alpha (B) mediates
tissue damage, and IL-10 (D) is anti-inflammatory.
Question 11: Which of the following is a compensatory mechanism in heart failure?
a. Decreased cardiac output
b. Activation of the renin-angiotensin-aldosterone system
c. Reduced sympathetic activity
d. Peripheral vasodilation
3
Practice Questions and Rationalized Correct Answers
Question 1: Which of the following is the primary cause of cellular injury in hypoxia?
a. Increased oxidative phosphorylation
b. Depletion of ATP
c. Excessive calcium influx
d. Mitochondrial hyperplasia
Correct Answer: B. Depletion of ATP
Explanation: Hypoxia leads to insufficient oxygen supply, impairing aerobic metabolism
and reducing ATP production. ATP depletion disrupts cellular processes, includ-
ing ion pumps, causing cellular injury. Increased oxidative phosphorylation (A)
requires oxygen, excessive calcium influx (C) is a secondary effect, and mitochon-
drial hyperplasia (D) is not a direct consequence of hypoxia.
Question 2: What is the hallmark feature of apoptosis?
a. Cellular swelling
b. Chromatin condensation
c. Membrane rupture
d. Inflammatory response
Correct Answer: B. Chromatin condensation
Explanation: Apoptosis is programmed cell death characterized by chromatin
condensation, DNA fragmentation, and cell shrinkage without inflammation. Cel-
lular swelling (A) and membrane rupture (C) occur in necrosis, and apoptosis
typically does not trigger an inflammatory response (D).
Question 3: Which electrolyte imbalance is most commonly associated with cardiac arrhyth-
mias?
a. Hypernatremia
b. Hypokalemia
c. Hypermagnesemia
d. Hypocalcemia
Correct Answer: B. Hypokalemia
Explanation: Hypokalemia lowers potassium levels, altering membrane poten-
tials and predisposing to cardiac arrhythmias. Hypernatremia (A) affects fluid
balance, hypermagnesemia (C) may cause bradycardia, and hypocalcemia (D)
can lead to tetany but is less directly linked to arrhythmias.
Question 4: In which condition is Kussmaul breathing most likely observed?
a. Metabolic acidosis
1
, b. Respiratory alkalosis
c. Chronic obstructive pulmonary disease
d. Pulmonary edema
Correct Answer: A. Metabolic acidosis
Explanation: Kussmaul breathing is a compensatory hyperventilation seen in
metabolic acidosis to eliminate excess carbon dioxide and reduce acidity. Respi-
ratory alkalosis (B) involves hypoventilation, COPD (C) causes hypoventilation,
and pulmonary edema (D) leads to labored breathing but not typically Kussmaul’s
pattern.
Question 5: What is the primary source of energy for erythrocytes?
a. Oxidative phosphorylation
b. Glycolysis
c. Krebs cycle
d. Beta-oxidation
Correct Answer: B. Glycolysis
Explanation: Erythrocytes lack mitochondria, relying on anaerobic glycolysis
for ATP production. Oxidative phosphorylation (A) and the Krebs cycle (C) re-
quire mitochondria, and beta-oxidation (D) occurs in other cell types for fatty acid
metabolism.
Question 6: Which type of necrosis is most commonly associated with tuberculosis?
a. Coagulative
b. Liquefactive
c. Caseous
d. Fat
Correct Answer: C. Caseous
Explanation: Caseous necrosis, characterized by a cheese-like appearance, is
typical in tuberculosis due to granulomatous inflammation. Coagulative necrosis
(A) occurs in ischemic tissues, liquefactive necrosis (B) in bacterial infections or
brain tissue, and fat necrosis (D) in pancreatic or breast tissue injury.
Question 7: What is the primary pathophysiological mechanism of type 1 diabetes mellitus?
a. Insulin resistance
b. Autoimmune destruction of beta cells
c. Increased glucagon secretion
d. Impaired glucose uptake
Correct Answer: B. Autoimmune destruction of beta cells
Explanation: Type 1 diabetes results from autoimmune destruction of pancreatic
beta cells, leading to insulin deficiency. Insulin resistance (A) is characteristic
2
, of type 2 diabetes, increased glucagon secretion (C) is secondary, and impaired
glucose uptake (D) is a consequence, not the primary mechanism.
Question 8: Which of the following is a characteristic feature of chronic inflammation?
a. Neutrophil predominance
b. Tissue necrosis
c. Mononuclear cell infiltration
d. Exudate formation
Correct Answer: C. Mononuclear cell infiltration
Explanation: Chronic inflammation is marked by infiltration of mononuclear cells
(lymphocytes, macrophages). Neutrophils (A) predominate in acute inflammation,
tissue necrosis (B) is not always present, and exudate formation (D) is more typical
of acute inflammation.
Question 9: What is the most common cause of metabolic alkalosis?
a. Hyperventilation
b. Vomiting
c. Diarrhea
d. Renal failure
Correct Answer: B. Vomiting
Explanation: Vomiting causes loss of gastric acid, leading to metabolic alkalosis.
Hyperventilation (A) causes respiratory alkalosis, diarrhea (C) leads to metabolic
acidosis, and renal failure (D) typically causes metabolic acidosis due to impaired
acid excretion.
Question 10: Which cytokine is primarily responsible for the fever response in inflammation?
a. IL-2
b. TNF-alpha
c. IL-6
d. IL-10
Correct Answer: C. IL-6
Explanation: IL-6 stimulates the hypothalamus to increase body temperature dur-
ing inflammation. IL-2 (A) promotes T-cell proliferation, TNF-alpha (B) mediates
tissue damage, and IL-10 (D) is anti-inflammatory.
Question 11: Which of the following is a compensatory mechanism in heart failure?
a. Decreased cardiac output
b. Activation of the renin-angiotensin-aldosterone system
c. Reduced sympathetic activity
d. Peripheral vasodilation
3
