NR 507 Exam 3 Actual Exam V1 | NR 507 Advanced Pathophysiology
(NR507 Exam 3) [PDF] | Chamberlain University
1. A 45-year-old female presents with exophthalmos, tachycardia, and heat intolerance.
Laboratory results reveal low TSH and high T3/T4 levels. Which mechanism is primarily
responsible for her condition?
A. Autoimmune destruction of thyroid follicles
B. Pituitary adenoma secreting excessive TSH
C. Thyroid-stimulating immunoglobulins (TSI) binding to TSH receptors
D. Iodine deficiency leading to thyroid hypertrophy
Answer: C
Rationale: In Graves disease, thyroid-stimulating immunoglobulins (TSI) act as agonists
against the TSH receptors on the thyroid gland. This leads to the autonomous
overproduction of thyroid hormones, bypassing the normal pituitary feedback loop. The
resulting high levels of T3 and T4 suppress the secretion of TSH from the anterior pituitary,
explaining the laboratory findings.
2. A patient with Type 1 Diabetes Mellitus experiences hyperglycemia in the morning. Upon
checking blood glucose at 3:00 AM, the level is found to be 45 mg/dL. What is the most likely
cause of the morning hyperglycemia?
A. The Dawn Phenomenon
B. The Somogyi effect
C. Insufficient basal insulin coverage
D. Excessive carbohydrate intake before bed
Answer: B
Rationale: The Somogyi effect occurs when hypoglycemia during the night triggers a
counter-regulatory hormonal response, leading to rebound hyperglycemia in the morning.
Hormones such as epinephrine, cortisol, and glucagon are released to stimulate
gluconeogenesis and glycogenolysis. This is distinct from the Dawn Phenomenon, which
involves a rise in blood sugar without preceding hypoglycemia, primarily due to growth
hormone surges.
3. Which clinical manifestation is most characteristic of Syndrome of Inappropriate
Antidiuretic Hormone (SIADH)?
A. Hypernatremia and dehydration
B. Hyperkalemia and metabolic acidosis
,C. Polyuria and high urine specific gravity
D. Dilutional hyponatremia and serum hypoosmolality
Answer: D
Rationale: SIADH involves the excessive release of antidiuretic hormone (ADH), which
causes the kidneys to reabsorb water regardless of the body’s hydration status. This leads
to an expansion of the extracellular fluid volume and the dilution of sodium in the blood,
resulting in hyponatremia. Patients typically present with concentrated urine and low
serum osmolality due to the retention of free water.
4. A patient presents with central obesity, a ‘buffalo hump,’ and purple striae on the
abdomen. Which diagnostic finding would most strongly support a diagnosis of Cushing
Disease rather than Cushing Syndrome?
A. Elevated plasma ACTH levels secondary to a pituitary adenoma
B. Adrenal cortex atrophy
C. Elevated serum cortisol levels
D. Suppression of cortisol by low-dose dexamethasone
Answer: A
Rationale: Cushing Disease specifically refers to hypercortisolism caused by an ACTH-
secreting pituitary adenoma. While Cushing Syndrome describes the clinical manifestations
of excess cortisol from any source, the ‘disease’ subtype is defined by the pituitary origin.
High levels of ACTH stimulate the adrenal glands to produce excessive cortisol, and these
levels typically fail to suppress with low-dose dexamethasone but may suppress with high
doses.
5. A 60-year-old male with a history of chronic alcohol use presents with hematemesis and
esophageal varices. What is the primary hemodynamic mechanism contributing to this
condition?
A. Portal hypertension resulting from hepatic fibrosis
B. Decreased oncotic pressure due to hypoalbuminemia
C. Increased systemic arterial pressure
D. Activation of the renin-angiotensin-aldosterone system
Answer: A
Rationale: Chronic alcohol use leads to liver cirrhosis, characterized by extensive fibrosis
that obstructs blood flow through the liver. This obstruction increases the pressure within
the portal venous system, known as portal hypertension. To bypass the high-pressure
system, collateral circulation develops in the esophagus and stomach, leading to fragile
varices that are prone to rupture and bleeding.
, 6. A patient with Chronic Kidney Disease (CKD) develops secondary hyperparathyroidism.
What is the initiating factor for this metabolic disturbance?
A. Vitamin D toxicity
B. Hypocalcemia resulting from hyperphosphatemia and decreased Vitamin D activation
C. Direct stimulation of the parathyroid gland by urea
D. Loss of magnesium in the urine
Answer: B
Rationale: In CKD, the kidneys cannot effectively excrete phosphate, leading to
hyperphosphatemia, which inversely lowers serum calcium. Additionally, the damaged
kidneys fail to convert Vitamin D into its active form, further reducing calcium absorption
in the gut. The resulting chronic hypocalcemia persistently stimulates the parathyroid
glands to secrete PTH, leading to secondary hyperparathyroidism and bone
demineralization.
7. Which of the following describes the pathophysiology of Type 2 Diabetes Mellitus?
A. Absolute insulin deficiency due to autoimmune beta-cell destruction
B. Genetic mutation of the GLUT-4 transporter
C. Insulin resistance and relative insulin deficiency
D. Excessive production of glucagon from alpha cells alone
Answer: C
Rationale: Type 2 Diabetes Mellitus is characterized by a combination of peripheral insulin
resistance and progressive beta-cell dysfunction. Initially, the pancreas compensates by
secreting more insulin (hyperinsulinemia), but over time, the beta cells cannot maintain
this output. This leads to a relative insulin deficiency where the body cannot effectively
lower blood glucose levels despite the presence of some circulating insulin.
8. A patient is diagnosed with Addison’s Disease. Which of the following laboratory findings
would you expect to observe during an adrenal crisis?
A. Hyperglycemia and hypernatremia
B. Hypokalemia and hypertension
C. Decreased BUN and increased blood volume
D. Hyponatremia and hyperkalemia
Answer: D
Rationale: Addison’s Disease involves the destruction of the adrenal cortex, leading to a
deficiency in both cortisol and aldosterone. Aldosterone deficiency results in the inability of
(NR507 Exam 3) [PDF] | Chamberlain University
1. A 45-year-old female presents with exophthalmos, tachycardia, and heat intolerance.
Laboratory results reveal low TSH and high T3/T4 levels. Which mechanism is primarily
responsible for her condition?
A. Autoimmune destruction of thyroid follicles
B. Pituitary adenoma secreting excessive TSH
C. Thyroid-stimulating immunoglobulins (TSI) binding to TSH receptors
D. Iodine deficiency leading to thyroid hypertrophy
Answer: C
Rationale: In Graves disease, thyroid-stimulating immunoglobulins (TSI) act as agonists
against the TSH receptors on the thyroid gland. This leads to the autonomous
overproduction of thyroid hormones, bypassing the normal pituitary feedback loop. The
resulting high levels of T3 and T4 suppress the secretion of TSH from the anterior pituitary,
explaining the laboratory findings.
2. A patient with Type 1 Diabetes Mellitus experiences hyperglycemia in the morning. Upon
checking blood glucose at 3:00 AM, the level is found to be 45 mg/dL. What is the most likely
cause of the morning hyperglycemia?
A. The Dawn Phenomenon
B. The Somogyi effect
C. Insufficient basal insulin coverage
D. Excessive carbohydrate intake before bed
Answer: B
Rationale: The Somogyi effect occurs when hypoglycemia during the night triggers a
counter-regulatory hormonal response, leading to rebound hyperglycemia in the morning.
Hormones such as epinephrine, cortisol, and glucagon are released to stimulate
gluconeogenesis and glycogenolysis. This is distinct from the Dawn Phenomenon, which
involves a rise in blood sugar without preceding hypoglycemia, primarily due to growth
hormone surges.
3. Which clinical manifestation is most characteristic of Syndrome of Inappropriate
Antidiuretic Hormone (SIADH)?
A. Hypernatremia and dehydration
B. Hyperkalemia and metabolic acidosis
,C. Polyuria and high urine specific gravity
D. Dilutional hyponatremia and serum hypoosmolality
Answer: D
Rationale: SIADH involves the excessive release of antidiuretic hormone (ADH), which
causes the kidneys to reabsorb water regardless of the body’s hydration status. This leads
to an expansion of the extracellular fluid volume and the dilution of sodium in the blood,
resulting in hyponatremia. Patients typically present with concentrated urine and low
serum osmolality due to the retention of free water.
4. A patient presents with central obesity, a ‘buffalo hump,’ and purple striae on the
abdomen. Which diagnostic finding would most strongly support a diagnosis of Cushing
Disease rather than Cushing Syndrome?
A. Elevated plasma ACTH levels secondary to a pituitary adenoma
B. Adrenal cortex atrophy
C. Elevated serum cortisol levels
D. Suppression of cortisol by low-dose dexamethasone
Answer: A
Rationale: Cushing Disease specifically refers to hypercortisolism caused by an ACTH-
secreting pituitary adenoma. While Cushing Syndrome describes the clinical manifestations
of excess cortisol from any source, the ‘disease’ subtype is defined by the pituitary origin.
High levels of ACTH stimulate the adrenal glands to produce excessive cortisol, and these
levels typically fail to suppress with low-dose dexamethasone but may suppress with high
doses.
5. A 60-year-old male with a history of chronic alcohol use presents with hematemesis and
esophageal varices. What is the primary hemodynamic mechanism contributing to this
condition?
A. Portal hypertension resulting from hepatic fibrosis
B. Decreased oncotic pressure due to hypoalbuminemia
C. Increased systemic arterial pressure
D. Activation of the renin-angiotensin-aldosterone system
Answer: A
Rationale: Chronic alcohol use leads to liver cirrhosis, characterized by extensive fibrosis
that obstructs blood flow through the liver. This obstruction increases the pressure within
the portal venous system, known as portal hypertension. To bypass the high-pressure
system, collateral circulation develops in the esophagus and stomach, leading to fragile
varices that are prone to rupture and bleeding.
, 6. A patient with Chronic Kidney Disease (CKD) develops secondary hyperparathyroidism.
What is the initiating factor for this metabolic disturbance?
A. Vitamin D toxicity
B. Hypocalcemia resulting from hyperphosphatemia and decreased Vitamin D activation
C. Direct stimulation of the parathyroid gland by urea
D. Loss of magnesium in the urine
Answer: B
Rationale: In CKD, the kidneys cannot effectively excrete phosphate, leading to
hyperphosphatemia, which inversely lowers serum calcium. Additionally, the damaged
kidneys fail to convert Vitamin D into its active form, further reducing calcium absorption
in the gut. The resulting chronic hypocalcemia persistently stimulates the parathyroid
glands to secrete PTH, leading to secondary hyperparathyroidism and bone
demineralization.
7. Which of the following describes the pathophysiology of Type 2 Diabetes Mellitus?
A. Absolute insulin deficiency due to autoimmune beta-cell destruction
B. Genetic mutation of the GLUT-4 transporter
C. Insulin resistance and relative insulin deficiency
D. Excessive production of glucagon from alpha cells alone
Answer: C
Rationale: Type 2 Diabetes Mellitus is characterized by a combination of peripheral insulin
resistance and progressive beta-cell dysfunction. Initially, the pancreas compensates by
secreting more insulin (hyperinsulinemia), but over time, the beta cells cannot maintain
this output. This leads to a relative insulin deficiency where the body cannot effectively
lower blood glucose levels despite the presence of some circulating insulin.
8. A patient is diagnosed with Addison’s Disease. Which of the following laboratory findings
would you expect to observe during an adrenal crisis?
A. Hyperglycemia and hypernatremia
B. Hypokalemia and hypertension
C. Decreased BUN and increased blood volume
D. Hyponatremia and hyperkalemia
Answer: D
Rationale: Addison’s Disease involves the destruction of the adrenal cortex, leading to a
deficiency in both cortisol and aldosterone. Aldosterone deficiency results in the inability of
