,BIOL251/BIOL 251 Human Anatomy & Physiology I w/Lab
1. Which of the following best defines an endocrine gland?
A) A gland that secretes products into ducts
B) A ductless gland that secretes hormones directly into the bloodstream
C) A gland that releases enzymes for digestion
D) A gland that only secretes steroids
Correct Answer: A ductless gland that secretes hormones directly into the bloodstream
Rationale: Endocrine glands are ductless and release hormones directly into the interstitial fluid, which
then enter the bloodstream. Exocrine glands use ducts to secrete products onto epithelial surfaces.
Hormones are regulatory molecules, but not all are steroids.
2. Exocrine glands differ from endocrine glands because exocrine glands:
A) Release hormones into the blood
B) Have no ducts
C) Use ducts to secrete products onto epithelial surfaces
D) Only secrete steroids
Correct Answer: Use ducts to secrete products onto epithelial surfaces
Rationale: Exocrine glands secrete their products through ducts onto epithelial surfaces or into body
cavities. Examples include sweat, salivary, and digestive glands. Endocrine glands lack ducts and secrete
hormones directly into the blood.
3. Which of the following is an example of an exocrine gland?
A) Pituitary gland
B) Sweat gland
C) Thyroid gland
D) Adrenal gland
,Correct Answer: Sweat gland
Rationale: Sweat glands are exocrine glands because they secrete sweat through ducts onto the skin
surface. The pituitary, thyroid, and adrenal glands are endocrine glands that release hormones directly
into the bloodstream.
4. 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
Correct Answer: Regulate body processes through hormones
Rationale: The endocrine system uses hormones as chemical messengers to regulate metabolism,
growth, reproduction, and homeostasis. The nervous system transmits electrical signals, the digestive
system produces enzymes, and the immune system provides defense.
5. Which term describes a chemical messenger that is transported by the blood to distant target cells?
A) Neurotransmitter
B) Cytokine
C) Hormone
D) Enzyme
Correct Answer: Hormone
Rationale: Hormones are chemical messengers that travel through the bloodstream to exert effects on
distant target cells. Neurotransmitters act locally across synapses, cytokines are immune signaling
molecules, and enzymes catalyze biochemical reactions.
, 6. 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
Correct Answer: Hormone secretion directly into the bloodstream
Rationale: Endocrine glands are ductless and secrete hormones directly into the interstitial fluid, which
then enters the bloodstream. Exocrine glands secrete through ducts onto epithelial surfaces.
7. Hormones can be classified chemically into three major groups. Which of the following is NOT one of
them?
A) Steroids
B) Peptides/proteins
C) Amines
D) Nucleic acids
Correct Answer: Nucleic acids
Rationale: The three major chemical classes of hormones are steroids, peptides/proteins, and amines
(amino acid derivatives). Nucleic acids are not used as hormones in the body.
8. Which class of hormones is derived from cholesterol?
A) Peptide hormones
B) Amino acid-derived hormones
C) Steroid hormones
D) Glycoprotein hormones
Correct Answer: Steroid hormones
1. Which of the following best defines an endocrine gland?
A) A gland that secretes products into ducts
B) A ductless gland that secretes hormones directly into the bloodstream
C) A gland that releases enzymes for digestion
D) A gland that only secretes steroids
Correct Answer: A ductless gland that secretes hormones directly into the bloodstream
Rationale: Endocrine glands are ductless and release hormones directly into the interstitial fluid, which
then enter the bloodstream. Exocrine glands use ducts to secrete products onto epithelial surfaces.
Hormones are regulatory molecules, but not all are steroids.
2. Exocrine glands differ from endocrine glands because exocrine glands:
A) Release hormones into the blood
B) Have no ducts
C) Use ducts to secrete products onto epithelial surfaces
D) Only secrete steroids
Correct Answer: Use ducts to secrete products onto epithelial surfaces
Rationale: Exocrine glands secrete their products through ducts onto epithelial surfaces or into body
cavities. Examples include sweat, salivary, and digestive glands. Endocrine glands lack ducts and secrete
hormones directly into the blood.
3. Which of the following is an example of an exocrine gland?
A) Pituitary gland
B) Sweat gland
C) Thyroid gland
D) Adrenal gland
,Correct Answer: Sweat gland
Rationale: Sweat glands are exocrine glands because they secrete sweat through ducts onto the skin
surface. The pituitary, thyroid, and adrenal glands are endocrine glands that release hormones directly
into the bloodstream.
4. 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
Correct Answer: Regulate body processes through hormones
Rationale: The endocrine system uses hormones as chemical messengers to regulate metabolism,
growth, reproduction, and homeostasis. The nervous system transmits electrical signals, the digestive
system produces enzymes, and the immune system provides defense.
5. Which term describes a chemical messenger that is transported by the blood to distant target cells?
A) Neurotransmitter
B) Cytokine
C) Hormone
D) Enzyme
Correct Answer: Hormone
Rationale: Hormones are chemical messengers that travel through the bloodstream to exert effects on
distant target cells. Neurotransmitters act locally across synapses, cytokines are immune signaling
molecules, and enzymes catalyze biochemical reactions.
, 6. 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
Correct Answer: Hormone secretion directly into the bloodstream
Rationale: Endocrine glands are ductless and secrete hormones directly into the interstitial fluid, which
then enters the bloodstream. Exocrine glands secrete through ducts onto epithelial surfaces.
7. Hormones can be classified chemically into three major groups. Which of the following is NOT one of
them?
A) Steroids
B) Peptides/proteins
C) Amines
D) Nucleic acids
Correct Answer: Nucleic acids
Rationale: The three major chemical classes of hormones are steroids, peptides/proteins, and amines
(amino acid derivatives). Nucleic acids are not used as hormones in the body.
8. Which class of hormones is derived from cholesterol?
A) Peptide hormones
B) Amino acid-derived hormones
C) Steroid hormones
D) Glycoprotein hormones
Correct Answer: Steroid hormones
