MSN Advanced Pathophysiology 2 — Questions and Answers
Question 1: Cor pulmonale develops as a result of which underlying pathophysiological process?
- Left ventricular failure causing right-sided backup
- Pulmonary hypertension leading to right ventricular hypertrophy (Correct answer)
- Systemic hypertension overloading the right heart
- Mitral stenosis reducing right output
Correct answer: Pulmonary hypertension leading to right ventricular hypertrophy
Cor pulmonale is right heart disease caused by pulmonary hypertension, which increases afterload on the right ventricle leading to hypertrophy and eventual failure.
Question 2: In septic shock, which initial hemodynamic pattern is characteristically observed?
- High systemic vascular resistance with low cardiac output
- Low systemic vascular resistance with high cardiac output (warm shock) (Correct answer)
- Normal cardiac output with elevated central venous pressure
- Bradycardia with diastolic hypertension
Correct answer: Low systemic vascular resistance with high cardiac output (warm shock)
Early septic shock presents as warm shock with vasodilation, low SVR, and compensatory high cardiac output due to cytokine-mediated vasodilation.
Question 3: Which pathophysiological change causes the Kussmaul breathing pattern in diabetic ketoacidosis?
- Metabolic alkalosis stimulating the respiratory center
- Metabolic acidosis stimulating chemoreceptors to increase ventilation (Correct answer)
- Hypoxemia triggering peripheral chemoreceptors
- Hypernatremia affecting central osmoreceptors
Correct answer: Metabolic acidosis stimulating chemoreceptors to increase ventilation
The metabolic acidosis of DKA stimulates central and peripheral chemoreceptors, driving compensatory hyperventilation (Kussmaul respirations) to blow off CO2.
Question 4: Atherosclerosis formation begins with which initial pathological event?
- Smooth muscle cell proliferation
- Endothelial dysfunction and LDL infiltration into the intima (Correct answer)
- Platelet aggregation at intact vessel walls
- Calcification of the tunica media
Correct answer: Endothelial dysfunction and LDL infiltration into the intima
Atherosclerosis is initiated by endothelial dysfunction, which allows LDL to infiltrate the intima and undergo oxidation, triggering an inflammatory cascade.
Question 5: A patient with chronic liver disease develops hepatic encephalopathy. Which substance primarily contributes to neurological dysfunction?
- Elevated direct bilirubin crossing the blood-brain barrier
- Ammonia accumulating due to impaired hepatic urea cycle (Correct answer)
- Excess cortisol from adrenal insufficiency
- Hypoglycemia from glycogen depletion
Correct answer: Ammonia accumulating due to impaired hepatic urea cycle
Impaired hepatic ammonia detoxification leads to hyperammonemia; ammonia crosses the blood-brain barrier and disrupts neurotransmission, causing encephalopathy.
Question 6: In obstructive lung disease, which change to the flow-volume loop is most characteristic?
- Decreased total lung capacity with elevated residual volume
- Scooped-out (concave) expiratory curve with reduced peak expiratory flow (Correct answer)
- Tall, narrow loop with reduced total area
- Flattened inspiratory loop with normal expiratory curve
Correct answer: Scooped-out (concave) expiratory curve with reduced peak expiratory flow
Obstructive diseases like COPD and asthma produce airflow limitation during exhalation, creating the characteristic scooped or concave appearance on the expiratory limb.
MSN Advanced Pathophysiology 2
Cor pulmonale develops as a result of which underlying pathophysiological process?