BIOL 252 Human Anatomy & Physiology
II w/Lab Module 1 Exam: Endocrine
System 100 Questions with Correct
Answers and Expert Rationales
SECTION A: Overview and Mechanisms of Hormone Action
(Questions 1-25)
1. The study of hormones and their actions is called:
A) Neurology
B) Endocrinology
C) Immunology
D) Histology
Correct Answer: B) Endocrinology
Expert Rationale: Endocrinology is the study of hormones and the
endocrine glands that produce them. Hormones are chemical
messengers that travel through the bloodstream to target cells,
regulating various physiological processes. Neurology is the study of
the nervous system, immunology studies the immune system, and
histology studies tissues .
2. Hormones are chemical messengers that:
,A) Travel through the bloodstream to target cells
B) Travel through neurons to target cells
C) Are released only in response to stress
D) Are produced only by the brain
Correct Answer: A) Travel through the bloodstream to target
cells
Expert Rationale: Hormones are secreted by endocrine glands into
the blood and travel to distant target cells where they bind to
specific receptors. They regulate metabolism, growth, reproduction,
and homeostasis. Neurotransmitters travel via synaptic clefts, and
hormones are produced by various glands throughout the body .
3. Which of the following is a characteristic of water-soluble
hormones?
A) They bind to intracellular receptors
B) They can cross the plasma membrane easily
C) They bind to cell surface receptors and use second messengers
D) They bind to DNA directly
Correct Answer: C) They bind to cell surface receptors and
use second messengers
Expert Rationale: Water-soluble hormones (peptides, proteins,
catecholamines) cannot cross the plasma membrane and bind to
receptors on the cell surface. This triggers intracellular signaling
cascades via second messengers like cAMP. Lipid-soluble hormones
(steroids, thyroid hormones) cross the membrane and bind to
intracellular receptors .
,4. Lipid-soluble hormones typically bind to receptors located
in the:
A) Cell membrane
B) Cytoplasm or nucleus
C) Extracellular fluid
D) Bloodstream
Correct Answer: B) Cytoplasm or nucleus
Expert Rationale: Lipid-soluble hormones (steroid hormones and
thyroid hormones) can diffuse across the plasma membrane and
bind to intracellular receptors in the cytoplasm or nucleus. The
hormone-receptor complex then acts as a transcription factor to
regulate gene expression .
5. Which of the following is an example of a peptide
hormone?
A) Cortisol
B) Testosterone
C) Insulin
D) Aldosterone
Correct Answer: C) Insulin
Expert Rationale: Insulin is a peptide hormone composed of amino
acids. Cortisol, testosterone, and aldosterone are steroid hormones
derived from cholesterol and are lipid-soluble. Peptide hormones
are water-soluble and bind to cell surface receptors .
, 6. The second messenger system is used by:
A) Steroid hormones
B) Thyroid hormones
C) Peptide hormones
D) Cortisol
Correct Answer: C) Peptide hormones
Expert Rationale: Peptide hormones (water-soluble) cannot enter
cells and therefore use second messenger systems (like cAMP, IP3,
DAG) to relay signals inside the cell. Steroid and thyroid hormones
are lipid-soluble and can enter cells directly to alter gene expression
.
7. The primary second messenger for many water-soluble
hormones is:
A) Calcium
B) Cyclic AMP (cAMP)
C) DAG
D) IP3
Correct Answer: B) Cyclic AMP (cAMP)
Expert Rationale: Cyclic AMP (cAMP) is the most common second
messenger for water-soluble hormones. Hormone binding to a G-
protein coupled receptor activates adenylyl cyclase, which converts
ATP to cAMP, activating protein kinase A (PKA) .
II w/Lab Module 1 Exam: Endocrine
System 100 Questions with Correct
Answers and Expert Rationales
SECTION A: Overview and Mechanisms of Hormone Action
(Questions 1-25)
1. The study of hormones and their actions is called:
A) Neurology
B) Endocrinology
C) Immunology
D) Histology
Correct Answer: B) Endocrinology
Expert Rationale: Endocrinology is the study of hormones and the
endocrine glands that produce them. Hormones are chemical
messengers that travel through the bloodstream to target cells,
regulating various physiological processes. Neurology is the study of
the nervous system, immunology studies the immune system, and
histology studies tissues .
2. Hormones are chemical messengers that:
,A) Travel through the bloodstream to target cells
B) Travel through neurons to target cells
C) Are released only in response to stress
D) Are produced only by the brain
Correct Answer: A) Travel through the bloodstream to target
cells
Expert Rationale: Hormones are secreted by endocrine glands into
the blood and travel to distant target cells where they bind to
specific receptors. They regulate metabolism, growth, reproduction,
and homeostasis. Neurotransmitters travel via synaptic clefts, and
hormones are produced by various glands throughout the body .
3. Which of the following is a characteristic of water-soluble
hormones?
A) They bind to intracellular receptors
B) They can cross the plasma membrane easily
C) They bind to cell surface receptors and use second messengers
D) They bind to DNA directly
Correct Answer: C) They bind to cell surface receptors and
use second messengers
Expert Rationale: Water-soluble hormones (peptides, proteins,
catecholamines) cannot cross the plasma membrane and bind to
receptors on the cell surface. This triggers intracellular signaling
cascades via second messengers like cAMP. Lipid-soluble hormones
(steroids, thyroid hormones) cross the membrane and bind to
intracellular receptors .
,4. Lipid-soluble hormones typically bind to receptors located
in the:
A) Cell membrane
B) Cytoplasm or nucleus
C) Extracellular fluid
D) Bloodstream
Correct Answer: B) Cytoplasm or nucleus
Expert Rationale: Lipid-soluble hormones (steroid hormones and
thyroid hormones) can diffuse across the plasma membrane and
bind to intracellular receptors in the cytoplasm or nucleus. The
hormone-receptor complex then acts as a transcription factor to
regulate gene expression .
5. Which of the following is an example of a peptide
hormone?
A) Cortisol
B) Testosterone
C) Insulin
D) Aldosterone
Correct Answer: C) Insulin
Expert Rationale: Insulin is a peptide hormone composed of amino
acids. Cortisol, testosterone, and aldosterone are steroid hormones
derived from cholesterol and are lipid-soluble. Peptide hormones
are water-soluble and bind to cell surface receptors .
, 6. The second messenger system is used by:
A) Steroid hormones
B) Thyroid hormones
C) Peptide hormones
D) Cortisol
Correct Answer: C) Peptide hormones
Expert Rationale: Peptide hormones (water-soluble) cannot enter
cells and therefore use second messenger systems (like cAMP, IP3,
DAG) to relay signals inside the cell. Steroid and thyroid hormones
are lipid-soluble and can enter cells directly to alter gene expression
.
7. The primary second messenger for many water-soluble
hormones is:
A) Calcium
B) Cyclic AMP (cAMP)
C) DAG
D) IP3
Correct Answer: B) Cyclic AMP (cAMP)
Expert Rationale: Cyclic AMP (cAMP) is the most common second
messenger for water-soluble hormones. Hormone binding to a G-
protein coupled receptor activates adenylyl cyclase, which converts
ATP to cAMP, activating protein kinase A (PKA) .
