NR507 ADVANCED
PATHOPHYSIOLOGY EXAM 3:
ENDOCRINE, RENAL, AND
HEMATOLOGIC SYSTEMS QUESTIONS
AND VERIFIED ANSWERS | 100%
CORRECT | GRADE A+
1. A patient presents with a serum sodium level of 120 mEq/L and extremely concentrated
urine. Which pathophysiological mechanism most likely explains these findings?
A. Ectopic secretion of ADH by a tumor
B. Decreased production of antidiuretic hormone (ADH)
C. Destruction of the posterior pituitary gland
D. Insensitivity of the renal tubules to ADH
Answer: A
Conceptual Explanation: Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is
characterized by high ADH levels despite low serum osmolality, leading to water retention,
dilutional hyponatremia, and concentrated urine. Ectopic production (e.g., from small cell
lung cancer) is a common cause.
,2. Which clinical manifestation is uniquely characteristic of Graves’ disease compared to
other forms of hyperthyroidism?
A. Exophthalmos
B. Heat intolerance
C. Tachycardia and palpitations
D. Weight loss with increased appetite
Answer: A
Conceptual Explanation: Exophthalmos (bulging eyes) is specific to Graves’ disease due to
orbital edema and extraocular muscle enlargement caused by autoimmune stimulation of
the fibroblasts, which is not seen in other forms of hyperthyroidism.
3. A patient with Chronic Kidney Disease (CKD) develops secondary hyperparathyroidism.
What is the primary cause of this condition?
A. Excessive excretion of calcium by the kidneys
B. Direct destruction of the parathyroid glands by uremic toxins
C. Inability to activate Vitamin D and hyperphosphatemia
D. Hypersecretion of parathyroid-related protein (PTHrP) by the kidneys
Answer: C
Conceptual Explanation: In CKD, decreased GFR leads to phosphate retention and the
inability of the kidneys to convert Vitamin D to its active form (calcitriol). Both
, hypocalcemia and hyperphosphatemia stimulate the parathyroid glands to overproduce
PTH.
4. Which diagnostic finding is the hallmark of Diabetic Ketoacidosis (DKA) but not
Hyperosmolar Hyperglycemic State (HHS)?
A. Blood glucose levels above 600 mg/dL
B. Severe dehydration and polyuria
C. Kussmaul respirations and metabolic acidosis
D. High serum osmolality
Answer: C
Conceptual Explanation: DKA involves fat breakdown due to absolute insulin deficiency,
leading to ketone production and metabolic acidosis. Kussmaul respirations are a
compensatory mechanism to blow off CO2. HHS usually involves enough insulin to prevent
ketosis.
5. In Cushing’s Disease, the hypercortisolism is specifically caused by which of the following?
A. A pituitary adenoma secreting ACTH
B. An adrenal adenoma
C. Exogenous glucocorticoid use
D. Ectopic secretion of cortisol by a lung tumor
Answer: A
PATHOPHYSIOLOGY EXAM 3:
ENDOCRINE, RENAL, AND
HEMATOLOGIC SYSTEMS QUESTIONS
AND VERIFIED ANSWERS | 100%
CORRECT | GRADE A+
1. A patient presents with a serum sodium level of 120 mEq/L and extremely concentrated
urine. Which pathophysiological mechanism most likely explains these findings?
A. Ectopic secretion of ADH by a tumor
B. Decreased production of antidiuretic hormone (ADH)
C. Destruction of the posterior pituitary gland
D. Insensitivity of the renal tubules to ADH
Answer: A
Conceptual Explanation: Syndrome of Inappropriate Antidiuretic Hormone (SIADH) is
characterized by high ADH levels despite low serum osmolality, leading to water retention,
dilutional hyponatremia, and concentrated urine. Ectopic production (e.g., from small cell
lung cancer) is a common cause.
,2. Which clinical manifestation is uniquely characteristic of Graves’ disease compared to
other forms of hyperthyroidism?
A. Exophthalmos
B. Heat intolerance
C. Tachycardia and palpitations
D. Weight loss with increased appetite
Answer: A
Conceptual Explanation: Exophthalmos (bulging eyes) is specific to Graves’ disease due to
orbital edema and extraocular muscle enlargement caused by autoimmune stimulation of
the fibroblasts, which is not seen in other forms of hyperthyroidism.
3. A patient with Chronic Kidney Disease (CKD) develops secondary hyperparathyroidism.
What is the primary cause of this condition?
A. Excessive excretion of calcium by the kidneys
B. Direct destruction of the parathyroid glands by uremic toxins
C. Inability to activate Vitamin D and hyperphosphatemia
D. Hypersecretion of parathyroid-related protein (PTHrP) by the kidneys
Answer: C
Conceptual Explanation: In CKD, decreased GFR leads to phosphate retention and the
inability of the kidneys to convert Vitamin D to its active form (calcitriol). Both
, hypocalcemia and hyperphosphatemia stimulate the parathyroid glands to overproduce
PTH.
4. Which diagnostic finding is the hallmark of Diabetic Ketoacidosis (DKA) but not
Hyperosmolar Hyperglycemic State (HHS)?
A. Blood glucose levels above 600 mg/dL
B. Severe dehydration and polyuria
C. Kussmaul respirations and metabolic acidosis
D. High serum osmolality
Answer: C
Conceptual Explanation: DKA involves fat breakdown due to absolute insulin deficiency,
leading to ketone production and metabolic acidosis. Kussmaul respirations are a
compensatory mechanism to blow off CO2. HHS usually involves enough insulin to prevent
ketosis.
5. In Cushing’s Disease, the hypercortisolism is specifically caused by which of the following?
A. A pituitary adenoma secreting ACTH
B. An adrenal adenoma
C. Exogenous glucocorticoid use
D. Ectopic secretion of cortisol by a lung tumor
Answer: A
