A & P2 STRAIGHTERLINE FINAL EXAM 2026/2027 | 150
Questions and Answers with Complete Solutions | Anatomy
and Physiology II | Human Biology | Clinical Correlations |
Pass Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female patient presents with weight gain, cold intolerance, dry skin,
and elevated TSH levels. Laboratory studies show decreased T3 and T4. Which
endocrine disorder best matches this clinical presentation?
A. Graves' disease with thyroid hormone excess
B. Hashimoto's thyroiditis causing primary hypothyroidism [CORRECT]
C. Pituitary adenoma secreting excess TSH
D. Iodine deficiency causing toxic goiter
Correct Answer: B
Rationale: The clinical presentation is classic for primary hypothyroidism: elevated TSH
(pituitary compensation for low thyroid hormones), decreased T3/T4, and symptoms of
metabolic slowing (cold intolerance, weight gain, dry skin). Hashimoto's thyroiditis is an
autoimmune destruction of thyroid tissue, the most common cause of hypothyroidism
in developed countries.
,Why others are incorrect: A) Graves' disease causes hyperthyroidism with heat
intolerance, weight loss, and suppressed TSH. C) A TSH-secreting pituitary adenoma
would cause elevated T3/T4 (secondary hyperthyroidism), not decreased levels. D)
Iodine deficiency can cause goiter but typically presents with variable thyroid function;
"toxic goiter" implies hyperthyroidism, not hypothyroidism.
Q2: A patient with Cushing's syndrome exhibits central obesity, moon facies, buffalo
hump, and striae. Laboratory testing reveals elevated cortisol levels that do not
suppress with low-dose dexamethasone but suppress with high-dose dexamethasone.
Where is the most likely pathology located?
A. Adrenal cortex adenoma
B. Ectopic ACTH-producing tumor (small cell lung cancer)
C. Pituitary ACTH-secreting adenoma (Cushing's disease) [CORRECT]
D. Primary adrenal hyperplasia
Correct Answer: C
Rationale: The high-dose dexamethasone suppression test distinguishes
pituitary-dependent Cushing's disease from other causes. Pituitary adenomas retain
partial negative feedback sensitivity to high-dose glucocorticoids, causing cortisol
suppression. ACTH-dependent Cushing's with this suppression pattern confirms a
pituitary source (Cushing's disease).
Why others are incorrect: A) Adrenal adenoma and D) Primary adrenal hyperplasia are
ACTH-independent; cortisol would not suppress with any dexamethasone dose. B)
Ectopic ACTH tumors (often lung carcinoma) are autonomous and do not suppress with
high-dose dexamethasone.
,Q3: Which hormone pair correctly matches the hormone with its primary mechanism of
action on target cells?
A. Insulin — binds intracellular nuclear receptors to alter gene transcription
B. Epinephrine — activates G-protein coupled receptors and second messenger cAMP
[CORRECT]
C. Cortisol — binds cell surface receptors activating tyrosine kinase
D. Thyroid hormone — binds membrane receptors activating ion channels
Correct Answer: B
Rationale: Epinephrine is a catecholamine (amine hormone) that binds β-adrenergic
G-protein coupled receptors, activating adenylyl cyclase and increasing cAMP as a
second messenger. This mechanism allows rapid cellular responses.
Why others are incorrect: A) Insulin binds tyrosine kinase receptors (cell surface), not
nuclear receptors. C) Cortisol is a steroid hormone that diffuses into cells and binds
nuclear receptors to alter gene transcription. D) Thyroid hormone (T3/T4) enters cells
and binds intracellular nuclear receptors; while T3 can have non-genomic effects, its
primary mechanism is genomic.
Q4: A 28-year-old male presents with polyuria, polydipsia, and dilute urine (low specific
gravity). Water deprivation test shows no concentration of urine, but administration of
ADH (vasopressin) corrects the condition. Which condition is present?
A. Nephrogenic diabetes insipidus
B. Psychogenic polydipsia
, C. Central diabetes insipidus [CORRECT]
D. Syndrome of inappropriate ADH secretion (SIADH)
Correct Answer: C
Rationale: Central diabetes insipidus results from ADH deficiency (posterior pituitary or
hypothalamic dysfunction). The diagnostic pattern is: inability to concentrate urine with
water deprivation + response to exogenous ADH administration. This distinguishes it
from nephrogenic DI where kidneys don't respond to ADH.
Why others are incorrect: A) Nephrogenic DI would not respond to ADH administration
(kidney resistance). B) Psychogenic polydipsia would show urine concentration with
water deprivation (suppressed ADH is physiological, not pathological). D) SIADH causes
water retention, dilutional hyponatremia, and concentrated urine—opposite of this
presentation.
Q5: The hypothalamic-pituitary-thyroid (HPT) axis demonstrates which type of feedback
regulation?
A. Positive feedback with amplification of hormone signals
B. Negative feedback maintaining hormone homeostasis [CORRECT]
C. Feed-forward regulation anticipating metabolic needs
D. No feedback; hormones act independently
Correct Answer: B
Rationale: The HPT axis exemplifies negative feedback: TRH from hypothalamus
stimulates TSH from anterior pituitary, which stimulates T3/T4 from thyroid. Elevated
Questions and Answers with Complete Solutions | Anatomy
and Physiology II | Human Biology | Clinical Correlations |
Pass Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female patient presents with weight gain, cold intolerance, dry skin,
and elevated TSH levels. Laboratory studies show decreased T3 and T4. Which
endocrine disorder best matches this clinical presentation?
A. Graves' disease with thyroid hormone excess
B. Hashimoto's thyroiditis causing primary hypothyroidism [CORRECT]
C. Pituitary adenoma secreting excess TSH
D. Iodine deficiency causing toxic goiter
Correct Answer: B
Rationale: The clinical presentation is classic for primary hypothyroidism: elevated TSH
(pituitary compensation for low thyroid hormones), decreased T3/T4, and symptoms of
metabolic slowing (cold intolerance, weight gain, dry skin). Hashimoto's thyroiditis is an
autoimmune destruction of thyroid tissue, the most common cause of hypothyroidism
in developed countries.
,Why others are incorrect: A) Graves' disease causes hyperthyroidism with heat
intolerance, weight loss, and suppressed TSH. C) A TSH-secreting pituitary adenoma
would cause elevated T3/T4 (secondary hyperthyroidism), not decreased levels. D)
Iodine deficiency can cause goiter but typically presents with variable thyroid function;
"toxic goiter" implies hyperthyroidism, not hypothyroidism.
Q2: A patient with Cushing's syndrome exhibits central obesity, moon facies, buffalo
hump, and striae. Laboratory testing reveals elevated cortisol levels that do not
suppress with low-dose dexamethasone but suppress with high-dose dexamethasone.
Where is the most likely pathology located?
A. Adrenal cortex adenoma
B. Ectopic ACTH-producing tumor (small cell lung cancer)
C. Pituitary ACTH-secreting adenoma (Cushing's disease) [CORRECT]
D. Primary adrenal hyperplasia
Correct Answer: C
Rationale: The high-dose dexamethasone suppression test distinguishes
pituitary-dependent Cushing's disease from other causes. Pituitary adenomas retain
partial negative feedback sensitivity to high-dose glucocorticoids, causing cortisol
suppression. ACTH-dependent Cushing's with this suppression pattern confirms a
pituitary source (Cushing's disease).
Why others are incorrect: A) Adrenal adenoma and D) Primary adrenal hyperplasia are
ACTH-independent; cortisol would not suppress with any dexamethasone dose. B)
Ectopic ACTH tumors (often lung carcinoma) are autonomous and do not suppress with
high-dose dexamethasone.
,Q3: Which hormone pair correctly matches the hormone with its primary mechanism of
action on target cells?
A. Insulin — binds intracellular nuclear receptors to alter gene transcription
B. Epinephrine — activates G-protein coupled receptors and second messenger cAMP
[CORRECT]
C. Cortisol — binds cell surface receptors activating tyrosine kinase
D. Thyroid hormone — binds membrane receptors activating ion channels
Correct Answer: B
Rationale: Epinephrine is a catecholamine (amine hormone) that binds β-adrenergic
G-protein coupled receptors, activating adenylyl cyclase and increasing cAMP as a
second messenger. This mechanism allows rapid cellular responses.
Why others are incorrect: A) Insulin binds tyrosine kinase receptors (cell surface), not
nuclear receptors. C) Cortisol is a steroid hormone that diffuses into cells and binds
nuclear receptors to alter gene transcription. D) Thyroid hormone (T3/T4) enters cells
and binds intracellular nuclear receptors; while T3 can have non-genomic effects, its
primary mechanism is genomic.
Q4: A 28-year-old male presents with polyuria, polydipsia, and dilute urine (low specific
gravity). Water deprivation test shows no concentration of urine, but administration of
ADH (vasopressin) corrects the condition. Which condition is present?
A. Nephrogenic diabetes insipidus
B. Psychogenic polydipsia
, C. Central diabetes insipidus [CORRECT]
D. Syndrome of inappropriate ADH secretion (SIADH)
Correct Answer: C
Rationale: Central diabetes insipidus results from ADH deficiency (posterior pituitary or
hypothalamic dysfunction). The diagnostic pattern is: inability to concentrate urine with
water deprivation + response to exogenous ADH administration. This distinguishes it
from nephrogenic DI where kidneys don't respond to ADH.
Why others are incorrect: A) Nephrogenic DI would not respond to ADH administration
(kidney resistance). B) Psychogenic polydipsia would show urine concentration with
water deprivation (suppressed ADH is physiological, not pathological). D) SIADH causes
water retention, dilutional hyponatremia, and concentrated urine—opposite of this
presentation.
Q5: The hypothalamic-pituitary-thyroid (HPT) axis demonstrates which type of feedback
regulation?
A. Positive feedback with amplification of hormone signals
B. Negative feedback maintaining hormone homeostasis [CORRECT]
C. Feed-forward regulation anticipating metabolic needs
D. No feedback; hormones act independently
Correct Answer: B
Rationale: The HPT axis exemplifies negative feedback: TRH from hypothalamus
stimulates TSH from anterior pituitary, which stimulates T3/T4 from thyroid. Elevated
