NSG 3280 Pathophysiology ACTUAL
EXAM 2026/2027 | Galen College of
Nursing | Exam 4 Practice Test | Verified
Q&A | Pass Guaranteed - A+ Graded
UNIT 1: ENDOCRINE SYSTEM
PATHOPHYSIOLOGY
(Questions 1-40)
Q1: A patient with diabetes insipidus (DI) following head trauma is admitted. Which
pathophysiological mechanism explains the massive polyuria seen in this condition?
A. Excessive ADH production causing water retention
B. Destruction of hypothalamic osmoreceptors leading to unregulated thirst
C. Insufficient ADH secretion or renal response to ADH, preventing water reabsorption in collecting
ducts [CORRECT]
D. Overproduction of aldosterone causing sodium and water loss
Correct Answer: C
Rationale: Diabetes insipidus results from either insufficient antidiuretic hormone (ADH) secretion by
the posterior pituitary (central DI) or renal resistance to ADH (nephrogenic DI). ADH normally binds to
,V2 receptors on principal cells of the collecting ducts, triggering aquaporin-2 insertion into apical
membranes. Without functional ADH signaling, water cannot be reabsorbed, resulting in massive
dilute urine output (up to 20 L/day), hypernatremia, and intense thirst. Head trauma damages the
hypothalamic-pituitary stalk or posterior pituitary, disrupting ADH synthesis/transport.
Galen Note: Galen emphasizes distinguishing DI from SIADH—remember DI = Dilute urine,
Dehydration, and ADH Deficiency.
Q2: Which laboratory findings are consistent with syndrome of inappropriate antidiuretic hormone
(SIADH)? Select all that apply.
A. Serum sodium 118 mEq/L
B. Serum osmolality 240 mOsm/kg
C. Urine osmolality >100 mOsm/kg despite low serum osmolality
D. All of the above [CORRECT]
Correct Answer: D
Rationale: SIADH involves inappropriate ADH secretion in response to non-osmotic stimuli
(malignancy, CNS disorders, medications). ADH causes water reabsorption without sodium retention,
diluting serum (hyponatremia <135 mEq/L, decreased serum osmolality <280 mOsm/kg). However,
urine remains inappropriately concentrated (>100 mOsm/kg, often >300) because ADH maximally
stimulates water reabsorption. This paradox—dilute blood with concentrated urine—is
pathognomonic. The expanded intravascular volume suppresses aldosterone and increases ANP,
causing natriuresis (urine sodium >20 mEq/L).
Galen Note: Key diagnostic triad for SIADH: hypotonic hyponatremia, inappropriately concentrated
urine, and clinical euvolemia.
Q3: A 45-year-old patient presents with fatigue, weight loss, hypotension, and hyperpigmentation of
skin creases. Laboratory studies show hyponatremia, hyperkalemia, and low cortisol. Which
pathophysiological process explains the hyperpigmentation?
,A. Excessive ACTH stimulation causing melanocyte activation
B. Elevated ACTH levels due to loss of negative feedback, with ACTH precursor (POMC) stimulating
melanocytes [CORRECT]
C. Direct adrenal destruction of melanin-producing cells
D. Secondary increase in MSH from pituitary hyperfunction
Correct Answer: B
Rationale: Primary adrenal insufficiency (Addison's disease) destroys adrenal cortex, eliminating
cortisol production. Without cortisol's negative feedback, hypothalamic CRH and pituitary ACTH rise
markedly. ACTH is cleaved from pro-opiomelanocortin (POMC), which also produces
melanocyte-stimulating hormone (MSH). High ACTH/MSH levels stimulate epidermal melanocytes,
causing bronze hyperpigmentation in sun-exposed areas, palmar creases, and mucous membranes.
The electrolyte abnormalities (hyponatremia/hyperkalemia) result from aldosterone deficiency
causing renal sodium wasting and potassium retention.
Galen Note: Hyperpigmentation distinguishes PRIMARY from SECONDARY adrenal
insufficiency—secondary lacks this feature because ACTH is low, not high.
Q4: A patient with Cushing's syndrome develops proximal muscle weakness and osteoporosis. Which
cortisol-mediated mechanism is responsible?
A. Increased protein anabolism and calcium absorption
B. Enhanced protein catabolism in muscle and inhibition of osteoblast function with increased bone
resorption [CORRECT]
C. Direct cortisol toxicity to neuromuscular junctions
D. Secondary hyperparathyroidism from renal calcium wasting
Correct Answer: B
, Rationale: Excess cortisol (from pituitary ACTH adenoma, adrenal tumor, or exogenous steroids)
causes protein catabolism, breaking down muscle proteins for gluconeogenesis—manifesting as
proximal myopathy (difficulty climbing stairs, rising from chairs). Cortisol also inhibits osteoblast
collagen synthesis and stimulates osteoclast activity, causing osteoporosis, particularly in trabecular
bone (vertebrae, ribs). Additionally, cortisol decreases calcium absorption and increases renal
calcium excretion, further compromising bone density.
Galen Note: Cushing's "5 P's": Purple striae, Proximal muscle weakness, Posterior subcapsular
cataracts, Poor wound healing, and Psychological disturbances.
Q5: Which of the following is the primary pathophysiological defect in Graves' disease?
A. TSH-secreting pituitary adenoma causing thyroid hyperplasia
B. Autoantibodies (TSI) binding to and activating TSH receptors, causing unregulated hormone
synthesis [CORRECT]
C. Destructive thyroiditis releasing preformed hormone
D. Iodine deficiency triggering compensatory hyperplasia
Correct Answer: B
Rationale: Graves' disease is an autoimmune disorder where IgG antibodies (thyroid-stimulating
immunoglobulins/TSI) mimic TSH by binding to TSH receptors on thyroid follicular cells. Unlike TSH,
which is regulated by negative feedback, TSI production is unregulated, causing continuous receptor
activation. This stimulates all aspects of thyroid function: iodide uptake, thyroglobulin synthesis,
thyroid hormone production (T3/T4), and thyroid vascularization/hyperplasia (goiter). The
hyperthyroidism is diffuse, not nodular, and extrathyroidal manifestations (ophthalmopathy,
dermopathy) result from shared antigens between thyroid and orbital tissues.
Galen Note: Graves' is the ONLY cause of hyperthyroidism with DIFFUSE goiter, OPHTHALMOPATHY,
and DERMOPATHY together—this triad is pathognomonic.
EXAM 2026/2027 | Galen College of
Nursing | Exam 4 Practice Test | Verified
Q&A | Pass Guaranteed - A+ Graded
UNIT 1: ENDOCRINE SYSTEM
PATHOPHYSIOLOGY
(Questions 1-40)
Q1: A patient with diabetes insipidus (DI) following head trauma is admitted. Which
pathophysiological mechanism explains the massive polyuria seen in this condition?
A. Excessive ADH production causing water retention
B. Destruction of hypothalamic osmoreceptors leading to unregulated thirst
C. Insufficient ADH secretion or renal response to ADH, preventing water reabsorption in collecting
ducts [CORRECT]
D. Overproduction of aldosterone causing sodium and water loss
Correct Answer: C
Rationale: Diabetes insipidus results from either insufficient antidiuretic hormone (ADH) secretion by
the posterior pituitary (central DI) or renal resistance to ADH (nephrogenic DI). ADH normally binds to
,V2 receptors on principal cells of the collecting ducts, triggering aquaporin-2 insertion into apical
membranes. Without functional ADH signaling, water cannot be reabsorbed, resulting in massive
dilute urine output (up to 20 L/day), hypernatremia, and intense thirst. Head trauma damages the
hypothalamic-pituitary stalk or posterior pituitary, disrupting ADH synthesis/transport.
Galen Note: Galen emphasizes distinguishing DI from SIADH—remember DI = Dilute urine,
Dehydration, and ADH Deficiency.
Q2: Which laboratory findings are consistent with syndrome of inappropriate antidiuretic hormone
(SIADH)? Select all that apply.
A. Serum sodium 118 mEq/L
B. Serum osmolality 240 mOsm/kg
C. Urine osmolality >100 mOsm/kg despite low serum osmolality
D. All of the above [CORRECT]
Correct Answer: D
Rationale: SIADH involves inappropriate ADH secretion in response to non-osmotic stimuli
(malignancy, CNS disorders, medications). ADH causes water reabsorption without sodium retention,
diluting serum (hyponatremia <135 mEq/L, decreased serum osmolality <280 mOsm/kg). However,
urine remains inappropriately concentrated (>100 mOsm/kg, often >300) because ADH maximally
stimulates water reabsorption. This paradox—dilute blood with concentrated urine—is
pathognomonic. The expanded intravascular volume suppresses aldosterone and increases ANP,
causing natriuresis (urine sodium >20 mEq/L).
Galen Note: Key diagnostic triad for SIADH: hypotonic hyponatremia, inappropriately concentrated
urine, and clinical euvolemia.
Q3: A 45-year-old patient presents with fatigue, weight loss, hypotension, and hyperpigmentation of
skin creases. Laboratory studies show hyponatremia, hyperkalemia, and low cortisol. Which
pathophysiological process explains the hyperpigmentation?
,A. Excessive ACTH stimulation causing melanocyte activation
B. Elevated ACTH levels due to loss of negative feedback, with ACTH precursor (POMC) stimulating
melanocytes [CORRECT]
C. Direct adrenal destruction of melanin-producing cells
D. Secondary increase in MSH from pituitary hyperfunction
Correct Answer: B
Rationale: Primary adrenal insufficiency (Addison's disease) destroys adrenal cortex, eliminating
cortisol production. Without cortisol's negative feedback, hypothalamic CRH and pituitary ACTH rise
markedly. ACTH is cleaved from pro-opiomelanocortin (POMC), which also produces
melanocyte-stimulating hormone (MSH). High ACTH/MSH levels stimulate epidermal melanocytes,
causing bronze hyperpigmentation in sun-exposed areas, palmar creases, and mucous membranes.
The electrolyte abnormalities (hyponatremia/hyperkalemia) result from aldosterone deficiency
causing renal sodium wasting and potassium retention.
Galen Note: Hyperpigmentation distinguishes PRIMARY from SECONDARY adrenal
insufficiency—secondary lacks this feature because ACTH is low, not high.
Q4: A patient with Cushing's syndrome develops proximal muscle weakness and osteoporosis. Which
cortisol-mediated mechanism is responsible?
A. Increased protein anabolism and calcium absorption
B. Enhanced protein catabolism in muscle and inhibition of osteoblast function with increased bone
resorption [CORRECT]
C. Direct cortisol toxicity to neuromuscular junctions
D. Secondary hyperparathyroidism from renal calcium wasting
Correct Answer: B
, Rationale: Excess cortisol (from pituitary ACTH adenoma, adrenal tumor, or exogenous steroids)
causes protein catabolism, breaking down muscle proteins for gluconeogenesis—manifesting as
proximal myopathy (difficulty climbing stairs, rising from chairs). Cortisol also inhibits osteoblast
collagen synthesis and stimulates osteoclast activity, causing osteoporosis, particularly in trabecular
bone (vertebrae, ribs). Additionally, cortisol decreases calcium absorption and increases renal
calcium excretion, further compromising bone density.
Galen Note: Cushing's "5 P's": Purple striae, Proximal muscle weakness, Posterior subcapsular
cataracts, Poor wound healing, and Psychological disturbances.
Q5: Which of the following is the primary pathophysiological defect in Graves' disease?
A. TSH-secreting pituitary adenoma causing thyroid hyperplasia
B. Autoantibodies (TSI) binding to and activating TSH receptors, causing unregulated hormone
synthesis [CORRECT]
C. Destructive thyroiditis releasing preformed hormone
D. Iodine deficiency triggering compensatory hyperplasia
Correct Answer: B
Rationale: Graves' disease is an autoimmune disorder where IgG antibodies (thyroid-stimulating
immunoglobulins/TSI) mimic TSH by binding to TSH receptors on thyroid follicular cells. Unlike TSH,
which is regulated by negative feedback, TSI production is unregulated, causing continuous receptor
activation. This stimulates all aspects of thyroid function: iodide uptake, thyroglobulin synthesis,
thyroid hormone production (T3/T4), and thyroid vascularization/hyperplasia (goiter). The
hyperthyroidism is diffuse, not nodular, and extrathyroidal manifestations (ophthalmopathy,
dermopathy) result from shared antigens between thyroid and orbital tissues.
Galen Note: Graves' is the ONLY cause of hyperthyroidism with DIFFUSE goiter, OPHTHALMOPATHY,
and DERMOPATHY together—this triad is pathognomonic.
