AANPCB AANPCB Pathophysiology 1 — Questions and Answers
Question 1: Which pathophysiological mechanism is primarily responsible for the development of type 2 diabetes mellitus?
- Autoimmune destruction of beta cells
- Insulin resistance with relative insulin deficiency (Correct answer)
- Excess glucagon secretion only
- Complete absence of insulin production
Correct answer: Insulin resistance with relative insulin deficiency
Type 2 diabetes results from peripheral insulin resistance combined with progressive beta-cell dysfunction leading to relative insulin deficiency.
Question 2: In heart failure with reduced ejection fraction (HFrEF), which compensatory mechanism initially maintains cardiac output but ultimately worsens the condition?
- Decreased heart rate
- Activation of the renin-angiotensin-aldosterone system (RAAS) (Correct answer)
- Reduced sympathetic tone
- Decreased preload
Correct answer: Activation of the renin-angiotensin-aldosterone system (RAAS)
RAAS activation causes sodium and water retention increasing preload and afterload, which provides short-term compensation but leads to long-term cardiac remodeling and deterioration.
Question 3: Which pathophysiological change underlies the development of hypertension in patients with chronic kidney disease (CKD)?
- Decreased erythropoietin production
- Sodium and water retention due to reduced GFR (Correct answer)
- Increased parathyroid hormone levels
- Decreased renin secretion
Correct answer: Sodium and water retention due to reduced GFR
Reduced glomerular filtration rate in CKD impairs sodium and water excretion, leading to volume expansion and elevated blood pressure.
Question 4: What is the primary pathophysiological mechanism in asthma that leads to airflow obstruction?
- Alveolar destruction
- Bronchospasm, mucosal edema, and mucus hypersecretion (Correct answer)
- Loss of elastic recoil
- Pulmonary vascular remodeling
Correct answer: Bronchospasm, mucosal edema, and mucus hypersecretion
Asthma is characterized by reversible airflow obstruction caused by bronchospasm, airway inflammation with mucosal edema, and excessive mucus production.
Question 5: In atherosclerosis, which event initiates plaque formation in arterial walls?
- Platelet aggregation at the vessel lumen
- Endothelial injury and LDL oxidation in the intima (Correct answer)
- Smooth muscle cell apoptosis
- Decreased HDL in the bloodstream
Correct answer: Endothelial injury and LDL oxidation in the intima
Atherosclerosis begins with endothelial dysfunction and oxidized LDL accumulation in the arterial intima, triggering an inflammatory cascade that leads to plaque development.
Question 6: Which pathophysiological change is most responsible for the polyuria seen in uncontrolled diabetes mellitus?
- Increased ADH secretion
- Osmotic diuresis due to glucosuria (Correct answer)
- Decreased aldosterone levels
- Reduced tubular sodium reabsorption
Correct answer: Osmotic diuresis due to glucosuria
When blood glucose exceeds the renal threshold, glucose spills into urine and causes osmotic diuresis, drawing water with it and producing large urine volumes.
AANPCB AANPCB Pathophysiology 1
Which pathophysiological mechanism is primarily responsible for the development of type 2 diabetes mellitus?