STRAIGHTERLINE A&P II EXAM 2026/2027 | 100% Correct
Answers with Complete Solutions | Human Anatomy &
Physiology II | Clinical Correlations | Homeostasis | Pass
Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female presents with fatigue, weight gain, cold intolerance, and a
goiter. Laboratory studies show elevated TSH and decreased free T4. Which gland is
primarily dysfunctional in this condition?
A. Anterior pituitary
B. Thyroid gland
C. Hypothalamus
D. Adrenal cortex
Correct Answer: B
Rationale: This patient presents with primary hypothyroidism, evidenced by elevated
TSH (thyroid-stimulating hormone) and decreased free T4 (thyroxine). The thyroid gland
itself is dysfunctional, unable to produce adequate thyroid hormone despite maximum
stimulation by the anterior pituitary. The elevated TSH represents a compensatory
attempt by the anterior pituitary (A) to stimulate the failing thyroid; the pituitary is
functioning appropriately. Hypothalamic dysfunction (C) would cause tertiary
hypothyroidism with decreased TRH, TSH, and T4. The adrenal cortex (D) produces
corticosteroids and is unrelated to this presentation. The negative feedback loop
between thyroid hormone and TSH is disrupted at the level of the thyroid gland.
,Q2: A patient with Cushing's syndrome presents with moon facies, buffalo hump, central
obesity, and purple striae. Which hormone is elevated in this condition?
A. Aldosterone
B. Cortisol
C. Epinephrine
D. Thyroid hormone
Correct Answer: B
Rationale: Cushing's syndrome results from chronic exposure to elevated
glucocorticoids, specifically cortisol. The clinical manifestations—central obesity, moon
facies, buffalo hump (dorsocervical fat pad), purple striae, thin skin, and muscle
wasting—reflect the catabolic and metabolic effects of excess cortisol (protein
breakdown, gluconeogenesis, lipolysis with central redistribution). Aldosterone (A)
excess causes Conn's syndrome with hypertension and hypokalemia but not the
characteristic body habitus changes. Epinephrine (C) excess causes
pheochromocytoma symptoms (headache, sweating, tachycardia). Thyroid hormone
excess (D) causes hypermetabolism, weight loss, and heat intolerance.
Q3: Which hormone is secreted by the posterior pituitary but synthesized in the
hypothalamus?
A. Growth hormone
B. Prolactin
C. Antidiuretic hormone (ADH)
D. Thyroid-stimulating hormone (TSH)
Correct Answer: C
Rationale: Antidiuretic hormone (ADH, vasopressin) is synthesized by neurosecretory
cells in the supraoptic and paraventricular nuclei of the hypothalamus, transported via
axons through the infundibulum (pituitary stalk), and stored/released from the posterior
pituitary (neurohypophysis). This makes the posterior pituitary essentially an extension
,of the hypothalamus. Growth hormone (A), prolactin (B), and TSH (D) are all synthesized
and secreted by the anterior pituitary (adenohypophysis) in response to hypothalamic
releasing hormones. ADH regulates water reabsorption in the collecting ducts of the
kidneys; deficiency causes diabetes insipidus.
Q4: A patient with Type 1 diabetes mellitus develops diabetic ketoacidosis (DKA). Which
hormone deficiency is responsible for this metabolic derangement?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine
Correct Answer: A
Rationale: Absolute insulin deficiency in Type 1 diabetes prevents glucose uptake by
cells, leading to hyperglycemia and cellular starvation. The body responds by breaking
down fats (lipolysis) for energy, producing ketone bodies (acetoacetic acid,
beta-hydroxybutyric acid) that cause metabolic acidosis. Without insulin, glucagon (B)
acts unopposed, promoting hepatic gluconeogenesis and ketogenesis. While stress
hormones cortisol (C) and epinephrine (D) exacerbate hyperglycemia, they are not the
primary deficiency. Insulin administration inhibits lipolysis and ketogenesis, reverses the
catabolic state, and allows glucose uptake, resolving DKA.
Q5: Which hormone is classified as a steroid hormone and acts by binding to
intracellular receptors that influence gene transcription?
A. Epinephrine
B. Insulin
C. Estrogen
D. Glucagon
, Correct Answer: C
Rationale: Estrogen is a steroid hormone derived from cholesterol, characterized by
being lipid-soluble and able to cross cell membranes. Steroid hormones bind to
intracellular receptors (cytoplasmic or nuclear), forming hormone-receptor complexes
that bind to DNA hormone response elements, altering gene transcription and protein
synthesis. This mechanism produces slow, prolonged effects (hours to days).
Epinephrine (A), insulin (B), and glucagon (D) are water-soluble hormones (amines or
peptides) that cannot cross membranes; they bind to cell surface receptors and act
through second messenger systems (cAMP, IP3/DAG) producing rapid effects (seconds
to minutes).
Q6: A patient with hyperparathyroidism develops kidney stones and bone
demineralization. Which mechanism explains these findings?
A. Decreased calcium absorption from the intestine
B. Increased calcium reabsorption from bone and decreased renal excretion
C. Decreased phosphate reabsorption from the kidney
D. Increased calcitonin secretion
Correct Answer: B
Rationale: Parathyroid hormone (PTH) maintains calcium homeostasis by: (1)
stimulating osteoclasts to resorb bone, releasing calcium and phosphate; (2) increasing
renal tubular reabsorption of calcium (decreasing urinary loss); and (3) activating
vitamin D to enhance intestinal calcium absorption. In hyperparathyroidism, excessive
PTH causes hypercalcemia through bone resorption (osteitis fibrosa cystica) and
reduced renal calcium excretion. The hypercalcemia leads to hypercalciuria and calcium
phosphate/oxalate kidney stones. PTH decreases phosphate reabsorption
(phosphaturia), causing hypophosphatemia (C), but this does not explain the bone and
renal findings. Calcitonin (D) opposes PTH and decreases in response to
hypercalcemia.
Answers with Complete Solutions | Human Anatomy &
Physiology II | Clinical Correlations | Homeostasis | Pass
Guaranteed - A+ Graded
Domain 1: Endocrine System (15 Questions)
Q1: A 45-year-old female presents with fatigue, weight gain, cold intolerance, and a
goiter. Laboratory studies show elevated TSH and decreased free T4. Which gland is
primarily dysfunctional in this condition?
A. Anterior pituitary
B. Thyroid gland
C. Hypothalamus
D. Adrenal cortex
Correct Answer: B
Rationale: This patient presents with primary hypothyroidism, evidenced by elevated
TSH (thyroid-stimulating hormone) and decreased free T4 (thyroxine). The thyroid gland
itself is dysfunctional, unable to produce adequate thyroid hormone despite maximum
stimulation by the anterior pituitary. The elevated TSH represents a compensatory
attempt by the anterior pituitary (A) to stimulate the failing thyroid; the pituitary is
functioning appropriately. Hypothalamic dysfunction (C) would cause tertiary
hypothyroidism with decreased TRH, TSH, and T4. The adrenal cortex (D) produces
corticosteroids and is unrelated to this presentation. The negative feedback loop
between thyroid hormone and TSH is disrupted at the level of the thyroid gland.
,Q2: A patient with Cushing's syndrome presents with moon facies, buffalo hump, central
obesity, and purple striae. Which hormone is elevated in this condition?
A. Aldosterone
B. Cortisol
C. Epinephrine
D. Thyroid hormone
Correct Answer: B
Rationale: Cushing's syndrome results from chronic exposure to elevated
glucocorticoids, specifically cortisol. The clinical manifestations—central obesity, moon
facies, buffalo hump (dorsocervical fat pad), purple striae, thin skin, and muscle
wasting—reflect the catabolic and metabolic effects of excess cortisol (protein
breakdown, gluconeogenesis, lipolysis with central redistribution). Aldosterone (A)
excess causes Conn's syndrome with hypertension and hypokalemia but not the
characteristic body habitus changes. Epinephrine (C) excess causes
pheochromocytoma symptoms (headache, sweating, tachycardia). Thyroid hormone
excess (D) causes hypermetabolism, weight loss, and heat intolerance.
Q3: Which hormone is secreted by the posterior pituitary but synthesized in the
hypothalamus?
A. Growth hormone
B. Prolactin
C. Antidiuretic hormone (ADH)
D. Thyroid-stimulating hormone (TSH)
Correct Answer: C
Rationale: Antidiuretic hormone (ADH, vasopressin) is synthesized by neurosecretory
cells in the supraoptic and paraventricular nuclei of the hypothalamus, transported via
axons through the infundibulum (pituitary stalk), and stored/released from the posterior
pituitary (neurohypophysis). This makes the posterior pituitary essentially an extension
,of the hypothalamus. Growth hormone (A), prolactin (B), and TSH (D) are all synthesized
and secreted by the anterior pituitary (adenohypophysis) in response to hypothalamic
releasing hormones. ADH regulates water reabsorption in the collecting ducts of the
kidneys; deficiency causes diabetes insipidus.
Q4: A patient with Type 1 diabetes mellitus develops diabetic ketoacidosis (DKA). Which
hormone deficiency is responsible for this metabolic derangement?
A. Insulin
B. Glucagon
C. Cortisol
D. Epinephrine
Correct Answer: A
Rationale: Absolute insulin deficiency in Type 1 diabetes prevents glucose uptake by
cells, leading to hyperglycemia and cellular starvation. The body responds by breaking
down fats (lipolysis) for energy, producing ketone bodies (acetoacetic acid,
beta-hydroxybutyric acid) that cause metabolic acidosis. Without insulin, glucagon (B)
acts unopposed, promoting hepatic gluconeogenesis and ketogenesis. While stress
hormones cortisol (C) and epinephrine (D) exacerbate hyperglycemia, they are not the
primary deficiency. Insulin administration inhibits lipolysis and ketogenesis, reverses the
catabolic state, and allows glucose uptake, resolving DKA.
Q5: Which hormone is classified as a steroid hormone and acts by binding to
intracellular receptors that influence gene transcription?
A. Epinephrine
B. Insulin
C. Estrogen
D. Glucagon
, Correct Answer: C
Rationale: Estrogen is a steroid hormone derived from cholesterol, characterized by
being lipid-soluble and able to cross cell membranes. Steroid hormones bind to
intracellular receptors (cytoplasmic or nuclear), forming hormone-receptor complexes
that bind to DNA hormone response elements, altering gene transcription and protein
synthesis. This mechanism produces slow, prolonged effects (hours to days).
Epinephrine (A), insulin (B), and glucagon (D) are water-soluble hormones (amines or
peptides) that cannot cross membranes; they bind to cell surface receptors and act
through second messenger systems (cAMP, IP3/DAG) producing rapid effects (seconds
to minutes).
Q6: A patient with hyperparathyroidism develops kidney stones and bone
demineralization. Which mechanism explains these findings?
A. Decreased calcium absorption from the intestine
B. Increased calcium reabsorption from bone and decreased renal excretion
C. Decreased phosphate reabsorption from the kidney
D. Increased calcitonin secretion
Correct Answer: B
Rationale: Parathyroid hormone (PTH) maintains calcium homeostasis by: (1)
stimulating osteoclasts to resorb bone, releasing calcium and phosphate; (2) increasing
renal tubular reabsorption of calcium (decreasing urinary loss); and (3) activating
vitamin D to enhance intestinal calcium absorption. In hyperparathyroidism, excessive
PTH causes hypercalcemia through bone resorption (osteitis fibrosa cystica) and
reduced renal calcium excretion. The hypercalcemia leads to hypercalciuria and calcium
phosphate/oxalate kidney stones. PTH decreases phosphate reabsorption
(phosphaturia), causing hypophosphatemia (C), but this does not explain the bone and
renal findings. Calcitonin (D) opposes PTH and decreases in response to
hypercalcemia.
