Which of the following is the most common cause of hyperthyroidism?
A) Hashimoto's thyroiditis
B) Graves' disease
C) Pituitary adenoma
D) Iatrogenic hypothyroidism
Answer: B) Graves' disease
Rationale:
Graves' disease is the most common cause of hyperthyroidism. It is an autoimmune disorder in which
the immune system produces antibodies that stimulate the thyroid gland, leading to an overproduction
of thyroid hormones. Hashimoto's thyroiditis is the most common cause of hypothyroidism. A pituitary
adenoma can result in secondary hyperthyroidism, but it is less common than Graves' disease.
2. Question:
A patient with a history of chronic alcoholism presents with asterixis and confusion. What is the most
likely diagnosis?
A) Hepatic encephalopathy
B) Wernicke-Korsakoff syndrome
C) Subdural hematoma
D) Stroke
Answer: A) Hepatic encephalopathy
Rationale:
Chronic alcoholism is a risk factor for hepatic encephalopathy, a condition where the liver fails to
detoxify ammonia, leading to brain dysfunction. Asterixis (flapping tremor) and confusion are
characteristic symptoms. Wernicke-Korsakoff syndrome is due to thiamine deficiency and presents with
different symptoms, such as ataxia and memory deficits.
3. Question:
In the context of diabetes mellitus, which of the following is the primary mechanism of action of
metformin?
A) Stimulating insulin secretion
B) Increasing insulin sensitivity
C) Inhibiting glucose production by the liver
D) Reducing insulin resistance in muscle cells
Answer: C) Inhibiting glucose production by the liver
Rationale:
Metformin primarily works by inhibiting hepatic gluconeogenesis (the production of glucose by the liver).
,While it does increase insulin sensitivity and has some effects on muscle cells, its main action is to
decrease glucose output from the liver, thus lowering blood glucose levels in type 2 diabetes.
4. Question:
Which of the following changes is most commonly observed in patients with chronic obstructive
pulmonary disease (COPD)?
A) Hyperventilation and decreased PaCO2
B) Hypoxemia and hypercapnia
C) Respiratory alkalosis
D) Decreased lung compliance
Answer: B) Hypoxemia and hypercapnia
Rationale:
In COPD, patients often experience both hypoxemia (low oxygen levels) and hypercapnia (elevated
carbon dioxide levels) due to impaired ventilation and gas exchange. Hypoventilation and reduced
diffusion capacity for oxygen contribute to this imbalance. Respiratory alkalosis and hyperventilation are
typically seen in acute respiratory distress or other pulmonary disorders.
5. Question:
Which of the following is the most significant risk factor for the development of chronic kidney disease
(CKD)?
A) Hypertension
B) Hyperlipidemia
C) Diabetes mellitus
D) Cigarette smoking
Answer: C) Diabetes mellitus
Rationale:
Diabetes mellitus, particularly poorly controlled type 2 diabetes, is the leading cause of chronic kidney
disease. Chronic hyperglycemia leads to glomerular damage and nephropathy. Hypertension is also a
significant risk factor and often coexists with diabetes, but diabetes is the primary cause.
6. Question:
Which of the following would be most expected in a patient with a history of systemic lupus
erythematosus (SLE)?
A) Hyperthyroidism
B) Hypercalcemia
C) Proteinuria
D) Hemolytic anemia
, Answer: C) Proteinuria
Rationale:
Proteinuria is commonly seen in patients with systemic lupus erythematosus (SLE) due to lupus nephritis,
which affects the kidneys. Hemolytic anemia can also occur in SLE, but proteinuria is more characteristic.
Hyperthyroidism and hypercalcemia are not typically associated with SLE.
7. Question:
Which of the following is a classic feature of myocardial infarction (MI) on an ECG?
A) Widened QRS complex
B) T wave inversion in multiple leads
C) ST segment elevation in contiguous leads
D) Prolonged PR interval
Answer: C) ST segment elevation in contiguous leads
Rationale:
ST segment elevation in contiguous leads is a hallmark sign of an acute myocardial infarction (MI). The ST
segment changes occur due to myocardial injury and are seen on an electrocardiogram (ECG). T wave
inversion and widened QRS complexes can also occur in other cardiac conditions but are not as specific
for MI.
8. Question:
Which of the following best describes the pathophysiology of type 1 diabetes mellitus?
A) Insulin resistance and decreased insulin secretion
B) Autoimmune destruction of beta cells in the pancreas
C) Insulin resistance with normal beta-cell function
D) Defective insulin receptor signaling
Answer: B) Autoimmune destruction of beta cells in the pancreas
Rationale:
Type 1 diabetes mellitus is characterized by the autoimmune destruction of insulin-producing beta cells
in the pancreas. This leads to absolute insulin deficiency. Type 2 diabetes involves insulin resistance and
impaired insulin secretion, but it is not caused by autoimmune destruction.
9. Question:
What is the primary cause of pulmonary edema in patients with left-sided heart failure?
A) Increased pulmonary capillary hydrostatic pressure
B) Decreased plasma oncotic pressure
C) Increased capillary permeability
D) Obstruction of large airways