, BIOL 252 Human Anatomy & Physiology II w/Lab | Module 6
Exam Review and Answers -Summary | LockDown Browser |
Portage Learning - 250 Questions
This rigorous exam assesses advanced understanding of the endocrine system, including hormone synthesis,
receptor signaling, feedback loops, and clinical pathologies. It demands integration of molecular mechanisms
with systemic physiology, reflecting Ivy League and R1 university standards. It contains 250 multiple-choice
questions, each with four distractors and a fully worked rationale that explains why the keyed answer is correct.
Content is organized into 11 focused sections: Endocrine System, Blood, Heart and Cardiovascular System, Blood
Vessels and Circulation, Lymphatic System and Immunity, Respiratory System, Digestive System, Metabolism and
Nutrition, Urinary System, Fluid, Electrolyte, and Acid-Base Balance, Reproductive System. Targeted learning
outcomes include: Analyze the molecular mechanisms of hormone action and signal transduction.; Evaluate the
integration of endocrine feedback loops in maintaining homeostasis.; Diagnose endocrine disorders based on
clinical and laboratory data.. Every item has been reviewed for clinical accuracy, current guidelines, and clarity
so that students can study with confidence and self-correct as they work through the bank. Use it as a high-yield
review immediately before the exam, or as a structured practice tool during the unit - the rationales double as
concise teaching notes. The recommended writing time is 3 hours, with a passing score of 70%. Aligned with
Complies with US university accreditation standards for advanced human physiology courses. standards and
reflects the question style commonly seen on accredited program examinations. Students consistently achieving
Section 1: Endocrine System (Questions 1-23)
1 A hormone that binds to an intracellular receptor directly activates transcription of
target genes. Which of the following best describes the immediate consequence of
this binding?
A) Activation of a G-protein and subsequent second messenger cascade
B) Dimerization of the receptor-hormone complex and binding to hormone
response elements
C) Phosphorylation of the receptor by a tyrosine kinase
D) Internalization of the receptor-hormone complex into lysosomes
Answer: B
Rationale: Intracellular receptors (e.g., for steroid hormones) are typically located in
the cytoplasm or nucleus. Upon hormone binding, they dimerize and translocate to
the nucleus, where they bind to hormone response elements on DNA to regulate
transcription. Option A describes membrane-bound receptor signaling. Option C is
typical of receptor tyrosine kinases. Option D describes receptor downregulation.
2 In a patient with a pituitary tumor secreting excess ACTH, which of the following
laboratory findings would be most consistent with chronic stimulation of the
adrenal cortex?
A) Elevated serum cortisol, suppressed CRH, suppressed ACTH (from tumor
autonomous secretion)
,B) Elevated serum cortisol, elevated CRH, suppressed ACTH
C) Suppressed serum cortisol, elevated CRH, elevated ACTH
D) Elevated serum cortisol, suppressed CRH, normal ACTH
Answer: A
Rationale: A pituitary tumor secreting ACTH (Cushing's disease) leads to high
cortisol, which suppresses hypothalamic CRH via negative feedback. The tumor's
ACTH secretion is autonomous and not suppressed by cortisol, so ACTH remains
elevated. Option B is incorrect because CRH is suppressed, not elevated. Option C
describes primary adrenal insufficiency. Option D is inconsistent because ACTH
should be elevated from the tumor.
3 Which of the following hormones exerts its primary effects by binding to a
receptor that functions as a ligand-gated ion channel?
A) Epinephrine
B) Thyroid hormone
C) Acetylcholine (at the neuromuscular junction)
D) Insulin
Answer: C
Rationale: Acetylcholine at the neuromuscular junction binds to nicotinic receptors,
which are ligand-gated ion channels that open to allow Na+ influx. Epinephrine and
insulin bind to G-protein-coupled receptors and receptor tyrosine kinases,
respectively. Thyroid hormone binds to intracellular receptors.
4 A researcher observes that a hormone's effect is blocked by a drug that inhibits
adenylyl cyclase. Which of the following receptor types is most likely involved?
A) Receptor tyrosine kinase
B) G-protein-coupled receptor (Gs or Gi)
C) Intracellular receptor
D) Ligand-gated ion channel
Answer: B
Rationale: Adenylyl cyclase is activated or inhibited by G-protein-coupled receptors
via Gs (stimulatory) or Gi (inhibitory) subunits. Blocking adenylyl cyclase would
interfere with the production of cAMP, a second messenger. Receptor tyrosine
kinases (A) activate Ras-MAPK pathways. Intracellular receptors (C) directly affect
transcription. Ligand-gated ion channels (D) alter membrane potential.
, 5 A patient presents with polyuria, polydipsia, and hyperglycemia. Laboratory tests
show low insulin levels and high glucagon levels. Which of the following
metabolic derangements is most likely contributing to the hyperglycemia?
A) Increased glycogen synthesis in the liver
B) Increased gluconeogenesis and glycogenolysis
C) Increased peripheral glucose uptake
D) Increased glycolysis in skeletal muscle
Answer: B
Rationale: Low insulin and high glucagon (as in type 1 diabetes) favor catabolic
states: glucagon stimulates gluconeogenesis and glycogenolysis in the liver, raising
blood glucose. Insulin normally promotes glycogen synthesis (A), glucose uptake
(C), and glycolysis (D), all of which would lower blood glucose.
6 Which of the following best explains why cortisol is considered a 'permissive'
hormone for the action of catecholamines on vascular smooth muscle?
A) Cortisol upregulates beta-adrenergic receptors on smooth muscle cells
B) Cortisol inhibits the breakdown of catecholamines by COMT
C) Cortisol increases the synthesis of catecholamines in the adrenal medulla
D) Cortisol enhances the coupling of G-proteins to adenylyl cyclase
Answer: A
Rationale: Cortisol's permissive effect allows catecholamines to exert their full
vasoconstrictive action. One mechanism is upregulation of adrenergic receptors
(particularly alpha-1) on vascular smooth muscle. Options B, C, and D are not
established as primary mechanisms for permissiveness.
7 A patient with a history of hypothyroidism is found to have a goiter. Laboratory
results show low T4 and T3, and elevated TSH. Which of the following is the
most likely cause?
A) Pituitary tumor secreting TSH
B) Autoimmune destruction of the thyroid (Hashimoto's thyroiditis)
C) Iodine deficiency
D) TSH receptor-blocking antibodies
Answer: B
Rationale: Hashimoto's thyroiditis leads to gradual destruction of thyroid tissue,
causing low thyroid hormones. The pituitary responds by increasing TSH secretion,
which can stimulate remaining thyroid tissue to enlarge (goiter). A pituitary tumor
(A) would cause high TSH with high T4/T3. Iodine deficiency (C) is rare in
Exam Review and Answers -Summary | LockDown Browser |
Portage Learning - 250 Questions
This rigorous exam assesses advanced understanding of the endocrine system, including hormone synthesis,
receptor signaling, feedback loops, and clinical pathologies. It demands integration of molecular mechanisms
with systemic physiology, reflecting Ivy League and R1 university standards. It contains 250 multiple-choice
questions, each with four distractors and a fully worked rationale that explains why the keyed answer is correct.
Content is organized into 11 focused sections: Endocrine System, Blood, Heart and Cardiovascular System, Blood
Vessels and Circulation, Lymphatic System and Immunity, Respiratory System, Digestive System, Metabolism and
Nutrition, Urinary System, Fluid, Electrolyte, and Acid-Base Balance, Reproductive System. Targeted learning
outcomes include: Analyze the molecular mechanisms of hormone action and signal transduction.; Evaluate the
integration of endocrine feedback loops in maintaining homeostasis.; Diagnose endocrine disorders based on
clinical and laboratory data.. Every item has been reviewed for clinical accuracy, current guidelines, and clarity
so that students can study with confidence and self-correct as they work through the bank. Use it as a high-yield
review immediately before the exam, or as a structured practice tool during the unit - the rationales double as
concise teaching notes. The recommended writing time is 3 hours, with a passing score of 70%. Aligned with
Complies with US university accreditation standards for advanced human physiology courses. standards and
reflects the question style commonly seen on accredited program examinations. Students consistently achieving
Section 1: Endocrine System (Questions 1-23)
1 A hormone that binds to an intracellular receptor directly activates transcription of
target genes. Which of the following best describes the immediate consequence of
this binding?
A) Activation of a G-protein and subsequent second messenger cascade
B) Dimerization of the receptor-hormone complex and binding to hormone
response elements
C) Phosphorylation of the receptor by a tyrosine kinase
D) Internalization of the receptor-hormone complex into lysosomes
Answer: B
Rationale: Intracellular receptors (e.g., for steroid hormones) are typically located in
the cytoplasm or nucleus. Upon hormone binding, they dimerize and translocate to
the nucleus, where they bind to hormone response elements on DNA to regulate
transcription. Option A describes membrane-bound receptor signaling. Option C is
typical of receptor tyrosine kinases. Option D describes receptor downregulation.
2 In a patient with a pituitary tumor secreting excess ACTH, which of the following
laboratory findings would be most consistent with chronic stimulation of the
adrenal cortex?
A) Elevated serum cortisol, suppressed CRH, suppressed ACTH (from tumor
autonomous secretion)
,B) Elevated serum cortisol, elevated CRH, suppressed ACTH
C) Suppressed serum cortisol, elevated CRH, elevated ACTH
D) Elevated serum cortisol, suppressed CRH, normal ACTH
Answer: A
Rationale: A pituitary tumor secreting ACTH (Cushing's disease) leads to high
cortisol, which suppresses hypothalamic CRH via negative feedback. The tumor's
ACTH secretion is autonomous and not suppressed by cortisol, so ACTH remains
elevated. Option B is incorrect because CRH is suppressed, not elevated. Option C
describes primary adrenal insufficiency. Option D is inconsistent because ACTH
should be elevated from the tumor.
3 Which of the following hormones exerts its primary effects by binding to a
receptor that functions as a ligand-gated ion channel?
A) Epinephrine
B) Thyroid hormone
C) Acetylcholine (at the neuromuscular junction)
D) Insulin
Answer: C
Rationale: Acetylcholine at the neuromuscular junction binds to nicotinic receptors,
which are ligand-gated ion channels that open to allow Na+ influx. Epinephrine and
insulin bind to G-protein-coupled receptors and receptor tyrosine kinases,
respectively. Thyroid hormone binds to intracellular receptors.
4 A researcher observes that a hormone's effect is blocked by a drug that inhibits
adenylyl cyclase. Which of the following receptor types is most likely involved?
A) Receptor tyrosine kinase
B) G-protein-coupled receptor (Gs or Gi)
C) Intracellular receptor
D) Ligand-gated ion channel
Answer: B
Rationale: Adenylyl cyclase is activated or inhibited by G-protein-coupled receptors
via Gs (stimulatory) or Gi (inhibitory) subunits. Blocking adenylyl cyclase would
interfere with the production of cAMP, a second messenger. Receptor tyrosine
kinases (A) activate Ras-MAPK pathways. Intracellular receptors (C) directly affect
transcription. Ligand-gated ion channels (D) alter membrane potential.
, 5 A patient presents with polyuria, polydipsia, and hyperglycemia. Laboratory tests
show low insulin levels and high glucagon levels. Which of the following
metabolic derangements is most likely contributing to the hyperglycemia?
A) Increased glycogen synthesis in the liver
B) Increased gluconeogenesis and glycogenolysis
C) Increased peripheral glucose uptake
D) Increased glycolysis in skeletal muscle
Answer: B
Rationale: Low insulin and high glucagon (as in type 1 diabetes) favor catabolic
states: glucagon stimulates gluconeogenesis and glycogenolysis in the liver, raising
blood glucose. Insulin normally promotes glycogen synthesis (A), glucose uptake
(C), and glycolysis (D), all of which would lower blood glucose.
6 Which of the following best explains why cortisol is considered a 'permissive'
hormone for the action of catecholamines on vascular smooth muscle?
A) Cortisol upregulates beta-adrenergic receptors on smooth muscle cells
B) Cortisol inhibits the breakdown of catecholamines by COMT
C) Cortisol increases the synthesis of catecholamines in the adrenal medulla
D) Cortisol enhances the coupling of G-proteins to adenylyl cyclase
Answer: A
Rationale: Cortisol's permissive effect allows catecholamines to exert their full
vasoconstrictive action. One mechanism is upregulation of adrenergic receptors
(particularly alpha-1) on vascular smooth muscle. Options B, C, and D are not
established as primary mechanisms for permissiveness.
7 A patient with a history of hypothyroidism is found to have a goiter. Laboratory
results show low T4 and T3, and elevated TSH. Which of the following is the
most likely cause?
A) Pituitary tumor secreting TSH
B) Autoimmune destruction of the thyroid (Hashimoto's thyroiditis)
C) Iodine deficiency
D) TSH receptor-blocking antibodies
Answer: B
Rationale: Hashimoto's thyroiditis leads to gradual destruction of thyroid tissue,
causing low thyroid hormones. The pituitary responds by increasing TSH secretion,
which can stimulate remaining thyroid tissue to enlarge (goiter). A pituitary tumor
(A) would cause high TSH with high T4/T3. Iodine deficiency (C) is rare in
