NUR 555 ADVANCED CLINICAL
PATHOPHYSIOLOGY
COMPREHENSIVE EXAMINATION
QUESTIONS AND ANSWERS
1. Which mechanism best explains the development of cellular swelling during hypoxic
injury?
A. Decreased membrane permeability to sodium ions
B. Increased protein synthesis leading to high intracellular osmotic pressure
C. Failure of the Na+/K+ ATPase pump leading to increased intracellular sodium
D. Efflux of potassium ions resulting in water movement into the cell
Answer: C
Conceptual Explanation: Hypoxia decreases ATP production, which causes the Na+/K+
pump to fail. Sodium remains inside the cell, creating an osmotic gradient that pulls water
into the cell, resulting in oncosis (cellular swelling).
2. In the context of epigenetics, how does DNA methylation typically affect gene expression?
A. It increases gene transcription by unwinding histones
,B. It silences gene expression by preventing transcription factor binding
C. It induces mutations in the DNA base sequence
D. It enhances the translation of mRNA in the cytoplasm
Answer: B
Conceptual Explanation: DNA methylation involves the attachment of a methyl group to
cytosine bases, which typically acts to silence genes by blocking the access of transcription
factors to the promoter region.
3. Which physiological trigger stimulates the release of renin from the juxtaglomerular cells?
A. Increased blood pressure in the afferent arteriole
B. Decreased sympathetic nervous system activity
C. Decreased sodium delivery to the macula densa
D. Increased plasma volume
Answer: C
Conceptual Explanation: Renin is released in response to decreased renal perfusion,
sympathetic stimulation, or decreased sodium/chloride concentration at the macula densa
in the distal tubule.
4. A patient presents with a pH of 7.25, PaCO2 of 30 mmHg, and HCO3- of 15 mEq/L. Which
compensatory mechanism is the body utilizing?
A. Renal retention of bicarbonate
, B. Renal excretion of hydrogen ions
C. Respiratory hyperventilation to decrease PaCO2
D. Respiratory hypoventilation to retain CO2
Answer: C
Conceptual Explanation: The patient has metabolic acidosis (low pH and low HCO3-). The
respiratory system compensates by increasing the rate and depth of breathing (Kussmaul
respirations) to ‘blow off’ CO2 and raise the pH.
5. Which type of hypersensitivity reaction is characterized by the activation of cytotoxic T-
cells against self-antigens, such as in Type 1 Diabetes Mellitus?
A. Type IV (Cell-mediated)
B. Type II (Tissue-specific)
C. Type III (Immune complex-mediated)
D. Type I (IgE-mediated)
Answer: A
Conceptual Explanation: Type IV hypersensitivity is a delayed, cell-mediated response
involving T-lymphocytes. In Type 1 Diabetes, CD8+ cytotoxic T-cells destroy insulin-
producing beta cells in the pancreas.
PATHOPHYSIOLOGY
COMPREHENSIVE EXAMINATION
QUESTIONS AND ANSWERS
1. Which mechanism best explains the development of cellular swelling during hypoxic
injury?
A. Decreased membrane permeability to sodium ions
B. Increased protein synthesis leading to high intracellular osmotic pressure
C. Failure of the Na+/K+ ATPase pump leading to increased intracellular sodium
D. Efflux of potassium ions resulting in water movement into the cell
Answer: C
Conceptual Explanation: Hypoxia decreases ATP production, which causes the Na+/K+
pump to fail. Sodium remains inside the cell, creating an osmotic gradient that pulls water
into the cell, resulting in oncosis (cellular swelling).
2. In the context of epigenetics, how does DNA methylation typically affect gene expression?
A. It increases gene transcription by unwinding histones
,B. It silences gene expression by preventing transcription factor binding
C. It induces mutations in the DNA base sequence
D. It enhances the translation of mRNA in the cytoplasm
Answer: B
Conceptual Explanation: DNA methylation involves the attachment of a methyl group to
cytosine bases, which typically acts to silence genes by blocking the access of transcription
factors to the promoter region.
3. Which physiological trigger stimulates the release of renin from the juxtaglomerular cells?
A. Increased blood pressure in the afferent arteriole
B. Decreased sympathetic nervous system activity
C. Decreased sodium delivery to the macula densa
D. Increased plasma volume
Answer: C
Conceptual Explanation: Renin is released in response to decreased renal perfusion,
sympathetic stimulation, or decreased sodium/chloride concentration at the macula densa
in the distal tubule.
4. A patient presents with a pH of 7.25, PaCO2 of 30 mmHg, and HCO3- of 15 mEq/L. Which
compensatory mechanism is the body utilizing?
A. Renal retention of bicarbonate
, B. Renal excretion of hydrogen ions
C. Respiratory hyperventilation to decrease PaCO2
D. Respiratory hypoventilation to retain CO2
Answer: C
Conceptual Explanation: The patient has metabolic acidosis (low pH and low HCO3-). The
respiratory system compensates by increasing the rate and depth of breathing (Kussmaul
respirations) to ‘blow off’ CO2 and raise the pH.
5. Which type of hypersensitivity reaction is characterized by the activation of cytotoxic T-
cells against self-antigens, such as in Type 1 Diabetes Mellitus?
A. Type IV (Cell-mediated)
B. Type II (Tissue-specific)
C. Type III (Immune complex-mediated)
D. Type I (IgE-mediated)
Answer: A
Conceptual Explanation: Type IV hypersensitivity is a delayed, cell-mediated response
involving T-lymphocytes. In Type 1 Diabetes, CD8+ cytotoxic T-cells destroy insulin-
producing beta cells in the pancreas.
