NR 507 Week 6 Exam Endocrine System
Disorders Questions and Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
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1. A patient with primary hypothyroidism is expected to have which
laboratory findings?
A. Decreased TSH and increased free T4
B. Increased TSH and decreased free T4
C. Increased TSH and increased free T4
D. Decreased TSH and decreased free T3
Correct Answer: B. Increased TSH and decreased free T4
Rationale: Primary hypothyroidism results from failure of the thyroid
gland to produce sufficient thyroid hormone. As circulating free T4
decreases, the anterior pituitary compensates by increasing secretion
of thyroid-stimulating hormone (TSH). This combination of elevated
TSH and decreased free T4 is the hallmark laboratory finding of
primary hypothyroidism.
, 2. Which hormone is primarily responsible for lowering serum
calcium levels?
A. Parathyroid hormone
B. Aldosterone
C. Calcitonin
D. Cortisol
Correct Answer: C. Calcitonin
Rationale: Calcitonin is secreted by the parafollicular (C) cells of the
thyroid gland. It lowers serum calcium by inhibiting osteoclast activity
and promoting calcium deposition into bone. Although calcitonin
plays a relatively minor role in adult calcium regulation compared
with parathyroid hormone, its physiologic effect is to decrease calcium
levels.
3. Graves disease is primarily caused by:
A. Destruction of thyroid follicles by T cells
B. Autoantibodies stimulating TSH receptors
C. Pituitary adenoma producing excess TSH
D. Iodine deficiency
,Correct Answer: B. Autoantibodies stimulating TSH receptors
Rationale: Graves disease is an autoimmune disorder characterized by
thyroid-stimulating immunoglobulins (TSIs) that bind to TSH receptors,
stimulating excessive production of thyroid hormones. This results in
hyperthyroidism, diffuse goiter, and sometimes ophthalmopathy.
4. Which clinical manifestation is most consistent with
hyperthyroidism?
A. Bradycardia
B. Cold intolerance
C. Weight gain
D. Heat intolerance
Correct Answer: D. Heat intolerance
Rationale: Excess thyroid hormone increases basal metabolic rate,
resulting in heat intolerance, sweating, weight loss, tachycardia,
anxiety, tremors, and hyperactivity. Heat intolerance is a classic
symptom of hyperthyroidism.
5. A patient with Hashimoto thyroiditis most commonly develops:
, A. Hyperthyroidism only
B. Hypothyroidism due to autoimmune destruction
C. Pituitary failure
D. Hyperparathyroidism
Correct Answer: B. Hypothyroidism due to autoimmune destruction
Rationale: Hashimoto thyroiditis is an autoimmune disorder in which
antibodies progressively destroy thyroid tissue, leading to decreased
production of thyroid hormones and eventual hypothyroidism. It is the
most common cause of hypothyroidism in iodine-sufficient regions.
6. Which hormone is secreted by the adrenal cortex?
A. Epinephrine
B. Norepinephrine
C. Cortisol
D. Dopamine
Correct Answer: C. Cortisol
Rationale: The adrenal cortex produces glucocorticoids (cortisol),
mineralocorticoids (aldosterone), and adrenal androgens. Epinephrine
and norepinephrine are produced by the adrenal medulla.
Disorders Questions and Correct Answers
(Verified Answers) Plus Rationales 2026 Q&A |
Instant Download Pdf
1. A patient with primary hypothyroidism is expected to have which
laboratory findings?
A. Decreased TSH and increased free T4
B. Increased TSH and decreased free T4
C. Increased TSH and increased free T4
D. Decreased TSH and decreased free T3
Correct Answer: B. Increased TSH and decreased free T4
Rationale: Primary hypothyroidism results from failure of the thyroid
gland to produce sufficient thyroid hormone. As circulating free T4
decreases, the anterior pituitary compensates by increasing secretion
of thyroid-stimulating hormone (TSH). This combination of elevated
TSH and decreased free T4 is the hallmark laboratory finding of
primary hypothyroidism.
, 2. Which hormone is primarily responsible for lowering serum
calcium levels?
A. Parathyroid hormone
B. Aldosterone
C. Calcitonin
D. Cortisol
Correct Answer: C. Calcitonin
Rationale: Calcitonin is secreted by the parafollicular (C) cells of the
thyroid gland. It lowers serum calcium by inhibiting osteoclast activity
and promoting calcium deposition into bone. Although calcitonin
plays a relatively minor role in adult calcium regulation compared
with parathyroid hormone, its physiologic effect is to decrease calcium
levels.
3. Graves disease is primarily caused by:
A. Destruction of thyroid follicles by T cells
B. Autoantibodies stimulating TSH receptors
C. Pituitary adenoma producing excess TSH
D. Iodine deficiency
,Correct Answer: B. Autoantibodies stimulating TSH receptors
Rationale: Graves disease is an autoimmune disorder characterized by
thyroid-stimulating immunoglobulins (TSIs) that bind to TSH receptors,
stimulating excessive production of thyroid hormones. This results in
hyperthyroidism, diffuse goiter, and sometimes ophthalmopathy.
4. Which clinical manifestation is most consistent with
hyperthyroidism?
A. Bradycardia
B. Cold intolerance
C. Weight gain
D. Heat intolerance
Correct Answer: D. Heat intolerance
Rationale: Excess thyroid hormone increases basal metabolic rate,
resulting in heat intolerance, sweating, weight loss, tachycardia,
anxiety, tremors, and hyperactivity. Heat intolerance is a classic
symptom of hyperthyroidism.
5. A patient with Hashimoto thyroiditis most commonly develops:
, A. Hyperthyroidism only
B. Hypothyroidism due to autoimmune destruction
C. Pituitary failure
D. Hyperparathyroidism
Correct Answer: B. Hypothyroidism due to autoimmune destruction
Rationale: Hashimoto thyroiditis is an autoimmune disorder in which
antibodies progressively destroy thyroid tissue, leading to decreased
production of thyroid hormones and eventual hypothyroidism. It is the
most common cause of hypothyroidism in iodine-sufficient regions.
6. Which hormone is secreted by the adrenal cortex?
A. Epinephrine
B. Norepinephrine
C. Cortisol
D. Dopamine
Correct Answer: C. Cortisol
Rationale: The adrenal cortex produces glucocorticoids (cortisol),
mineralocorticoids (aldosterone), and adrenal androgens. Epinephrine
and norepinephrine are produced by the adrenal medulla.
