Endocrine Physiology Exam Preparation
Questions 100 Questions with Answers &
Rationales | Latest 2026/27 | Instant Pdf
Download
This exam covers the physiology of the endocrine system,
including hormone synthesis, regulation, mechanisms of action,
and associated disorders
Section 1: General Principles of Endocrinology (Questions
1–15)
1. Which of the following best defines a hormone?
A. A chemical released by exocrine glands into ducts
B. A chemical messenger transported via the bloodstream to
distant target cells
C. A neurotransmitter released at a synapse
D. A paracrine factor that acts on adjacent cells
Correct Answer: B
Rationale: Hormones are classical endocrine messengers
,secreted into the bloodstream to act on distant target cells.
Paracrine/autocrine factors act locally.
2. The half-life of a hormone is determined primarily by:
A. Its rate of secretion
B. Its rate of clearance (metabolism and excretion)
C. The number of target cell receptors
D. The concentration of binding proteins
Correct Answer: B
Rationale: Half-life depends on clearance mechanisms (liver,
kidney, enzymatic degradation). Binding proteins prolong half-
life (e.g., thyroxine-binding globulin).
3. A hormone that binds to an intracellular nuclear receptor
typically has which characteristic?
A. Water-soluble, rapid onset, short duration
B. Lipid-soluble (steroid/thyroid), slower onset, longer duration
C. Peptide-based, acts via second messengers
D. Stored in large vesicles in the endocrine cell
Correct Answer: B
Rationale: Steroid and thyroid hormones are lipophilic, diffuse
,across membranes, bind to intracellular/ nuclear receptors, and
alter gene transcription (slow onset, prolonged effect).
4. The “permissive effect” of a hormone refers to:
A. One hormone inhibiting the action of another
B. One hormone requiring the presence of another to exert its
full effect
C. Two hormones producing a greater effect than the sum of
their individual effects
D. Hormone secretion occurring in pulses
Correct Answer: B
Rationale: Permissiveness: e.g., thyroid hormone increases β-
adrenergic receptor expression, allowing epinephrine to have
stronger effects.
5. Which of the following is an example of a positive
feedback loop in endocrinology?
A. TSH stimulation of thyroid hormone release, with thyroid
hormone inhibiting TSH
B. Oxytocin release during labor causing stronger contractions,
which further stimulate oxytocin release
C. Cortisol feedback inhibition of CRH and ACTH
D. Insulin lowering blood glucose, reducing insulin secretion
, Correct Answer: B
Rationale: Positive feedback amplifies the response (oxytocin
→ contractions → more oxytocin). Most hormonal regulation is
negative feedback.
6. Peptide hormones are typically synthesized as:
A. Preprohormones, then cleaved to prohormones, then active
hormone
B. Directly from cholesterol
C. Stored in the nucleus
D. Tyrosine derivatives only
Correct Answer: A
Rationale: Peptide hormones are synthesized as larger
precursors (preprohormone → prohormone → active hormone
in secretory vesicles).
7. Which second messenger is generated by activation of
adenylyl cyclase?
A. Inositol trisphosphate (IP₃)
B. Diacylglycerol (DAG)
C. Cyclic AMP (cAMP)
D. Calcium
Questions 100 Questions with Answers &
Rationales | Latest 2026/27 | Instant Pdf
Download
This exam covers the physiology of the endocrine system,
including hormone synthesis, regulation, mechanisms of action,
and associated disorders
Section 1: General Principles of Endocrinology (Questions
1–15)
1. Which of the following best defines a hormone?
A. A chemical released by exocrine glands into ducts
B. A chemical messenger transported via the bloodstream to
distant target cells
C. A neurotransmitter released at a synapse
D. A paracrine factor that acts on adjacent cells
Correct Answer: B
Rationale: Hormones are classical endocrine messengers
,secreted into the bloodstream to act on distant target cells.
Paracrine/autocrine factors act locally.
2. The half-life of a hormone is determined primarily by:
A. Its rate of secretion
B. Its rate of clearance (metabolism and excretion)
C. The number of target cell receptors
D. The concentration of binding proteins
Correct Answer: B
Rationale: Half-life depends on clearance mechanisms (liver,
kidney, enzymatic degradation). Binding proteins prolong half-
life (e.g., thyroxine-binding globulin).
3. A hormone that binds to an intracellular nuclear receptor
typically has which characteristic?
A. Water-soluble, rapid onset, short duration
B. Lipid-soluble (steroid/thyroid), slower onset, longer duration
C. Peptide-based, acts via second messengers
D. Stored in large vesicles in the endocrine cell
Correct Answer: B
Rationale: Steroid and thyroid hormones are lipophilic, diffuse
,across membranes, bind to intracellular/ nuclear receptors, and
alter gene transcription (slow onset, prolonged effect).
4. The “permissive effect” of a hormone refers to:
A. One hormone inhibiting the action of another
B. One hormone requiring the presence of another to exert its
full effect
C. Two hormones producing a greater effect than the sum of
their individual effects
D. Hormone secretion occurring in pulses
Correct Answer: B
Rationale: Permissiveness: e.g., thyroid hormone increases β-
adrenergic receptor expression, allowing epinephrine to have
stronger effects.
5. Which of the following is an example of a positive
feedback loop in endocrinology?
A. TSH stimulation of thyroid hormone release, with thyroid
hormone inhibiting TSH
B. Oxytocin release during labor causing stronger contractions,
which further stimulate oxytocin release
C. Cortisol feedback inhibition of CRH and ACTH
D. Insulin lowering blood glucose, reducing insulin secretion
, Correct Answer: B
Rationale: Positive feedback amplifies the response (oxytocin
→ contractions → more oxytocin). Most hormonal regulation is
negative feedback.
6. Peptide hormones are typically synthesized as:
A. Preprohormones, then cleaved to prohormones, then active
hormone
B. Directly from cholesterol
C. Stored in the nucleus
D. Tyrosine derivatives only
Correct Answer: A
Rationale: Peptide hormones are synthesized as larger
precursors (preprohormone → prohormone → active hormone
in secretory vesicles).
7. Which second messenger is generated by activation of
adenylyl cyclase?
A. Inositol trisphosphate (IP₃)
B. Diacylglycerol (DAG)
C. Cyclic AMP (cAMP)
D. Calcium
