BIOL251 Human Anatomy & Physiology I w/Lab Module 8:
Endocrine System Regulation – 70 Multiple-Choice
Questions & Answers Complete Exam Review – Portage
Learning | Latest 2026/2027 | 100% Verified
Module 8: Endocrine System Regulation
This module covers the endocrine system's role in regulating physiological processes and maintaining
homeostasis.
Endocrine Glands: Pituitary, thyroid, adrenal, pancreas, and gonads.
Hormone Functions: Chemical messengers that regulate growth, metabolism, and reproduction.
Feedback Mechanisms: Negative and positive feedback loops control hormone levels.
Clinical Correlations: Diabetes mellitus, hypothyroidism, and Cushing's syndrome.
This comprehensive document contains 70 multiple-choice questions and verified
answers for the Module 8 Exam covering the Endocrine System for Portage Learning's
BIOL251 Human Anatomy & Physiology I w/Lab. Each question includes the correct answer
in bold with a detailed italic explanation .
SECTION 1: HORMONE CHEMISTRY & MECHANISMS (Questions 1–15)
1. The primary function of the endocrine system is to:
A) Transmit electrical signals
B) Produce enzymes
C) Regulate body processes through hormones
D) Provide immune defense
Answer: C
,Hormones are chemical messengers released into the bloodstream to regulate metabolism,
growth, reproduction, and homeostasis .
2. Which characteristic best distinguishes endocrine glands from exocrine glands?
A) Presence of ducts
B) Secretion into body cavities
C) Hormone secretion directly into the bloodstream
D) Local effects only
Answer: C
Endocrine glands are ductless and secrete hormones directly into the interstitial fluid, which
then enters the bloodstream. Exocrine glands (e.g., sweat, salivary) release secretions
through ducts .
3. Which of the following is a catecholamine hormone?
A) Insulin
B) Cortisol
C) Epinephrine
D) Thyroxine
Answer: C
Catecholamines (epinephrine, norepinephrine, dopamine) are derived from the amino acid
tyrosine and are water-soluble. They are produced by the adrenal medulla .
4. Thyroid hormones (T3/T4) are synthesized from which amino acid?
A) Tryptophan
B) Tyrosine
C) Histidine
D) Methionine
Answer: B
Thyroid hormones are iodinated derivatives of the amino acid tyrosine. Iodine is
incorporated into thyroglobulin to form T3 and T4 .
, 5. Peptide hormones typically act through:
A) Intracellular receptors
B) Membrane-bound G-protein coupled receptors
C) Direct DNA binding
D) Nuclear receptors
Answer: B
Peptide hormones are water-soluble and cannot cross the plasma membrane. They bind to
membrane-bound receptors and activate second-messenger systems such as cAMP .
6. Steroid hormones are derived from:
A) Amino acids
B) Cholesterol
C) Carbohydrates
D) Fatty acids
Answer: B
Steroid hormones (cortisol, aldosterone, sex hormones) are cholesterol derivatives. They
are lipid-soluble and act through intracellular receptors .
7. Which hormone uses the JAK-STAT signaling pathway?
A) Insulin
B) Growth hormone
C) Epinephrine
D) Testosterone
Answer: B
Growth hormone binds to cytokine receptors, activating the JAK-STAT signaling pathway,
which leads to changes in gene expression .
8. Which of the following is an example of a lipid-soluble hormone?
Endocrine System Regulation – 70 Multiple-Choice
Questions & Answers Complete Exam Review – Portage
Learning | Latest 2026/2027 | 100% Verified
Module 8: Endocrine System Regulation
This module covers the endocrine system's role in regulating physiological processes and maintaining
homeostasis.
Endocrine Glands: Pituitary, thyroid, adrenal, pancreas, and gonads.
Hormone Functions: Chemical messengers that regulate growth, metabolism, and reproduction.
Feedback Mechanisms: Negative and positive feedback loops control hormone levels.
Clinical Correlations: Diabetes mellitus, hypothyroidism, and Cushing's syndrome.
This comprehensive document contains 70 multiple-choice questions and verified
answers for the Module 8 Exam covering the Endocrine System for Portage Learning's
BIOL251 Human Anatomy & Physiology I w/Lab. Each question includes the correct answer
in bold with a detailed italic explanation .
SECTION 1: HORMONE CHEMISTRY & MECHANISMS (Questions 1–15)
1. The primary function of the endocrine system is to:
A) Transmit electrical signals
B) Produce enzymes
C) Regulate body processes through hormones
D) Provide immune defense
Answer: C
,Hormones are chemical messengers released into the bloodstream to regulate metabolism,
growth, reproduction, and homeostasis .
2. Which characteristic best distinguishes endocrine glands from exocrine glands?
A) Presence of ducts
B) Secretion into body cavities
C) Hormone secretion directly into the bloodstream
D) Local effects only
Answer: C
Endocrine glands are ductless and secrete hormones directly into the interstitial fluid, which
then enters the bloodstream. Exocrine glands (e.g., sweat, salivary) release secretions
through ducts .
3. Which of the following is a catecholamine hormone?
A) Insulin
B) Cortisol
C) Epinephrine
D) Thyroxine
Answer: C
Catecholamines (epinephrine, norepinephrine, dopamine) are derived from the amino acid
tyrosine and are water-soluble. They are produced by the adrenal medulla .
4. Thyroid hormones (T3/T4) are synthesized from which amino acid?
A) Tryptophan
B) Tyrosine
C) Histidine
D) Methionine
Answer: B
Thyroid hormones are iodinated derivatives of the amino acid tyrosine. Iodine is
incorporated into thyroglobulin to form T3 and T4 .
, 5. Peptide hormones typically act through:
A) Intracellular receptors
B) Membrane-bound G-protein coupled receptors
C) Direct DNA binding
D) Nuclear receptors
Answer: B
Peptide hormones are water-soluble and cannot cross the plasma membrane. They bind to
membrane-bound receptors and activate second-messenger systems such as cAMP .
6. Steroid hormones are derived from:
A) Amino acids
B) Cholesterol
C) Carbohydrates
D) Fatty acids
Answer: B
Steroid hormones (cortisol, aldosterone, sex hormones) are cholesterol derivatives. They
are lipid-soluble and act through intracellular receptors .
7. Which hormone uses the JAK-STAT signaling pathway?
A) Insulin
B) Growth hormone
C) Epinephrine
D) Testosterone
Answer: B
Growth hormone binds to cytokine receptors, activating the JAK-STAT signaling pathway,
which leads to changes in gene expression .
8. Which of the following is an example of a lipid-soluble hormone?
