NSG 530 Exam 3 Actual Exam V3 | NSG 530 Advanced
Pathophysiology (NSG530 Exam 3) [PDF] | Wilkes University
1. A 65-year-old male with a history of small cell lung carcinoma presents with confusion and
serum sodium of 120 mEq/L. Which pathophysiologic mechanism most likely explains these
findings?
A. Excessive water intake due to psychogenic polydipsia
B. Reduced aldosterone secretion from the adrenal cortex
C. Ectopic production of antidiuretic hormone (ADH)
D. Osmotic diuresis secondary to hyperglycemia
Answer: C
Rationale: The patient’s presentation is consistent with the Syndrome of Inappropriate
Antidiuretic Hormone (SIADH), often caused by paraneoplastic syndromes in lung cancer.
In SIADH, high levels of ADH cause the renal collecting ducts to reabsorb excessive water
despite low serum osmolality. This leads to dilutional hyponatremia and neurologic
symptoms such as confusion or seizures.
2. A patient with chronic kidney disease (CKD) presents with a serum potassium of 6.8 mEq/L
and peaked T-waves on EKG. Which process is responsible for this electrolyte imbalance?
A. Increased potassium secretion in the distal tubule
B. Excessive activation of the renin-angiotensin-aldosterone system
C. Intracellular shifting of potassium due to metabolic alkalosis
D. Reduced glomerular filtration and tubular secretion of potassium
Answer: D
Rationale: Hyperkalemia is a common complication of advanced CKD because the kidneys
cannot effectively excrete potassium as the glomerular filtration rate (GFR) declines.
Additionally, as nephrons are lost, the total capacity for distal tubular secretion of
potassium is significantly reduced. This leads to dangerous accumulations in the
extracellular fluid, resulting in characteristic EKG changes like peaked T-waves.
3. A 42-year-old woman reports extreme fatigue, cold intolerance, and weight gain.
Laboratory tests show a high TSH level and low free T4. Which condition is the most likely
diagnosis?
A. Grave’s disease
B. Hashimoto thyroiditis
,C. Pituitary adenoma
D. Subacute thyroiditis
Answer: B
Rationale: Hashimoto thyroiditis is an autoimmune disorder characterized by the
destruction of the thyroid gland, leading to primary hypothyroidism. The elevated TSH
level indicates that the pituitary gland is attempting to stimulate a failing thyroid gland
through negative feedback mechanisms. Low free T4 confirms the gland’s inability to
produce sufficient hormone, distinguishing it from secondary causes.
4. A patient presents with polydipsia, polyuria, and a urine specific gravity of 1.002. After
administration of exogenous vasopressin, the urine osmolality increases significantly. What is
the diagnosis?
A. Nephrogenic diabetes insipidus
B. Central diabetes insipidus
C. Syndrome of inappropriate ADH
D. Primary polydipsia
Answer: B
Rationale: Central diabetes insipidus (DI) is caused by a deficiency in the production or
release of ADH from the posterior pituitary. The patient’s response to exogenous
vasopressin (ADH) indicates that the kidneys are capable of responding to the hormone,
confirming the defect is central rather than renal. Nephrogenic DI would show no
significant change in urine concentration after vasopressin administration.
5. A 55-year-old female presents with severe epigastric pain radiating to the back, nausea,
and elevated serum lipase. What is the most likely underlying mechanism of this condition?
A. Obstruction of the common bile duct by a gallstone
B. Ischemic necrosis of the intestinal mucosa
C. Infection by Helicobacter pylori in the gastric antrum
D. Auto-digestion of the gland by prematurely activated enzymes
Answer: D
Rationale: Acute pancreatitis involves the premature activation of pancreatic enzymes,
such as trypsin, within the pancreatic parenchyma itself. This results in auto-digestion of
the organ, leading to intense inflammation, edema, and potentially necrosis. Elevated
serum lipase is a specific biomarker for this pancreatic injury, and the pain pattern is
classic for this disorder.
, 6. Which finding is most characteristic of nephrotic syndrome, distinguishing it from nephritic
syndrome?
A. Gross hematuria and RBC casts
B. Hypertension and oliguria
C. Proteinuria exceeding 3.5 g/day
D. Increased serum creatinine and BUN
Answer: C
Rationale: Nephrotic syndrome is characterized by massive proteinuria, typically greater
than 3.5 grams per 24 hours, due to increased glomerular permeability. This loss of protein
leads to hypoalbuminemia and generalized edema. In contrast, nephritic syndrome is
primarily defined by inflammation, resulting in hematuria and RBC casts.
7. A patient with cirrhosis develops abdominal distension and shifting dullness on percussion.
What is the primary hemodynamic driver for this fluid accumulation?
A. Portal hypertension and hypoalbuminemia
B. Decreased capillary hydrostatic pressure
C. Increased capillary oncotic pressure
D. Systemic hypertension and sodium wasting
Answer: A
Rationale: Ascites in cirrhosis is driven by portal hypertension, which increases
hydrostatic pressure in the peritoneal capillaries. Simultaneously, the liver’s inability to
synthesize albumin leads to decreased plasma oncotic pressure, allowing fluid to leak into
the interstitial space. Activation of the renin-angiotensin-aldosterone system further
worsens this by promoting sodium and water retention.
8. A 28-year-old male with Type 1 Diabetes presents with Kussmaul respirations, fruity
breath, and a blood glucose of 450 mg/dL. What is the primary cause of his metabolic
acidosis?
A. Accumulation of beta-hydroxybutyrate and acetoacetate
B. Lactic acid accumulation from anaerobic metabolism
C. Retention of carbon dioxide due to hypoventilation
D. Loss of bicarbonate through the renal tubules
Answer: A
Rationale: Diabetic Ketoacidosis (DKA) occurs when a profound lack of insulin leads the
body to metabolize fats for energy, producing acidic ketone bodies like beta-
Pathophysiology (NSG530 Exam 3) [PDF] | Wilkes University
1. A 65-year-old male with a history of small cell lung carcinoma presents with confusion and
serum sodium of 120 mEq/L. Which pathophysiologic mechanism most likely explains these
findings?
A. Excessive water intake due to psychogenic polydipsia
B. Reduced aldosterone secretion from the adrenal cortex
C. Ectopic production of antidiuretic hormone (ADH)
D. Osmotic diuresis secondary to hyperglycemia
Answer: C
Rationale: The patient’s presentation is consistent with the Syndrome of Inappropriate
Antidiuretic Hormone (SIADH), often caused by paraneoplastic syndromes in lung cancer.
In SIADH, high levels of ADH cause the renal collecting ducts to reabsorb excessive water
despite low serum osmolality. This leads to dilutional hyponatremia and neurologic
symptoms such as confusion or seizures.
2. A patient with chronic kidney disease (CKD) presents with a serum potassium of 6.8 mEq/L
and peaked T-waves on EKG. Which process is responsible for this electrolyte imbalance?
A. Increased potassium secretion in the distal tubule
B. Excessive activation of the renin-angiotensin-aldosterone system
C. Intracellular shifting of potassium due to metabolic alkalosis
D. Reduced glomerular filtration and tubular secretion of potassium
Answer: D
Rationale: Hyperkalemia is a common complication of advanced CKD because the kidneys
cannot effectively excrete potassium as the glomerular filtration rate (GFR) declines.
Additionally, as nephrons are lost, the total capacity for distal tubular secretion of
potassium is significantly reduced. This leads to dangerous accumulations in the
extracellular fluid, resulting in characteristic EKG changes like peaked T-waves.
3. A 42-year-old woman reports extreme fatigue, cold intolerance, and weight gain.
Laboratory tests show a high TSH level and low free T4. Which condition is the most likely
diagnosis?
A. Grave’s disease
B. Hashimoto thyroiditis
,C. Pituitary adenoma
D. Subacute thyroiditis
Answer: B
Rationale: Hashimoto thyroiditis is an autoimmune disorder characterized by the
destruction of the thyroid gland, leading to primary hypothyroidism. The elevated TSH
level indicates that the pituitary gland is attempting to stimulate a failing thyroid gland
through negative feedback mechanisms. Low free T4 confirms the gland’s inability to
produce sufficient hormone, distinguishing it from secondary causes.
4. A patient presents with polydipsia, polyuria, and a urine specific gravity of 1.002. After
administration of exogenous vasopressin, the urine osmolality increases significantly. What is
the diagnosis?
A. Nephrogenic diabetes insipidus
B. Central diabetes insipidus
C. Syndrome of inappropriate ADH
D. Primary polydipsia
Answer: B
Rationale: Central diabetes insipidus (DI) is caused by a deficiency in the production or
release of ADH from the posterior pituitary. The patient’s response to exogenous
vasopressin (ADH) indicates that the kidneys are capable of responding to the hormone,
confirming the defect is central rather than renal. Nephrogenic DI would show no
significant change in urine concentration after vasopressin administration.
5. A 55-year-old female presents with severe epigastric pain radiating to the back, nausea,
and elevated serum lipase. What is the most likely underlying mechanism of this condition?
A. Obstruction of the common bile duct by a gallstone
B. Ischemic necrosis of the intestinal mucosa
C. Infection by Helicobacter pylori in the gastric antrum
D. Auto-digestion of the gland by prematurely activated enzymes
Answer: D
Rationale: Acute pancreatitis involves the premature activation of pancreatic enzymes,
such as trypsin, within the pancreatic parenchyma itself. This results in auto-digestion of
the organ, leading to intense inflammation, edema, and potentially necrosis. Elevated
serum lipase is a specific biomarker for this pancreatic injury, and the pain pattern is
classic for this disorder.
, 6. Which finding is most characteristic of nephrotic syndrome, distinguishing it from nephritic
syndrome?
A. Gross hematuria and RBC casts
B. Hypertension and oliguria
C. Proteinuria exceeding 3.5 g/day
D. Increased serum creatinine and BUN
Answer: C
Rationale: Nephrotic syndrome is characterized by massive proteinuria, typically greater
than 3.5 grams per 24 hours, due to increased glomerular permeability. This loss of protein
leads to hypoalbuminemia and generalized edema. In contrast, nephritic syndrome is
primarily defined by inflammation, resulting in hematuria and RBC casts.
7. A patient with cirrhosis develops abdominal distension and shifting dullness on percussion.
What is the primary hemodynamic driver for this fluid accumulation?
A. Portal hypertension and hypoalbuminemia
B. Decreased capillary hydrostatic pressure
C. Increased capillary oncotic pressure
D. Systemic hypertension and sodium wasting
Answer: A
Rationale: Ascites in cirrhosis is driven by portal hypertension, which increases
hydrostatic pressure in the peritoneal capillaries. Simultaneously, the liver’s inability to
synthesize albumin leads to decreased plasma oncotic pressure, allowing fluid to leak into
the interstitial space. Activation of the renin-angiotensin-aldosterone system further
worsens this by promoting sodium and water retention.
8. A 28-year-old male with Type 1 Diabetes presents with Kussmaul respirations, fruity
breath, and a blood glucose of 450 mg/dL. What is the primary cause of his metabolic
acidosis?
A. Accumulation of beta-hydroxybutyrate and acetoacetate
B. Lactic acid accumulation from anaerobic metabolism
C. Retention of carbon dioxide due to hypoventilation
D. Loss of bicarbonate through the renal tubules
Answer: A
Rationale: Diabetic Ketoacidosis (DKA) occurs when a profound lack of insulin leads the
body to metabolize fats for energy, producing acidic ketone bodies like beta-
