BIOL251 Human Anatomy & Physiology I w/Lab
2026 | Module 3: Cardiovascular System – Blood
Vessels Exam Review |70+ Questions and
Answers Summary |LockDown Browser |Portage
Learning
Module 3: Cardiovascular System – Blood Vessels
This module discusses the structure and function of blood vessels and the circulatory
pathways in the body.
Blood Vessel Types:
o Arteries: Carry blood away from the heart; thick muscular walls.
o Veins: Carry blood toward the heart; thinner walls, often with valves.
o Capillaries: Microscopic vessels for exchange of gases, nutrients, and
wastes.
Blood Pressure: The force exerted by blood on vessel walls, measured in mmHg.
Blood Flow Dynamics: Includes capillary exchange, resistance, and regulation by
neural and hormonal mechanisms.
Clinical Correlations: Hypertension, hypotension, and shock.
Example: Blood pressure readings are used to diagnose and monitor cardiovascular health.
Section 1: Structure of Blood Vessel Walls (Questions 1–10)
1. Which layer of a blood vessel wall is in direct contact with the blood flowing
through the lumen?
A) Tunica externa
B) Tunica media
,C) Tunica intima
D) Tunica adventitia
Answer: C) Tunica intima Explanation: The tunica intima is the innermost layer of a blood
vessel wall, making direct contact with the blood flowing through the lumen.
2. The tunica intima is structurally composed of which tissue types?
A) Simple columnar epithelium resting on skeletal muscle
B) Simple squamous epithelium (endothelium) resting on a thin basement membrane
C) Stratified squamous epithelium backed by dense irregular connective tissue
D) Smooth muscle and elastic fibers
Answer: B) Simple squamous epithelium (endothelium) resting on a thin basement
membrane Explanation: The tunica intima consists of a smooth lining of simple
squamous cells called endothelium, supported by a thin subendothelial layer of loose
connective tissue.
3. Which tunic layer is dominated by smooth muscle and elastic fibers, regulating
vessel diameter?
A) Tunica externa
B) Tunica intima
C) Tunica media
D) Vasa vasorum
Answer: C) Tunica media Explanation: The tunica media is the thick middle layer
composed primarily of circularly arranged smooth muscle cells and sheets of elastic fibers.
,4. Vasoconstriction and vasodilation are mediated by the smooth muscle located in
which layer of the vascular wall?
A) Tunica intima
B) Tunica media
C) Tunica externa
D) Tunica adventitia
Answer: B) Tunica media Explanation: Smooth muscle contraction (vasoconstriction) and
relaxation (vasodilation) are restricted to the tunica media, directly altering blood flow and
blood pressure.
5. Which branch of the nervous system primarily controls the smooth muscle in the
tunica media?
A) Somatic motor division
B) Sympathetic division of the autonomic nervous system
C) Parasympathetic division of the autonomic nervous system
D) Central nervous system somatic sensory fibers
Answer: B) Sympathetic division of the autonomic nervous system Explanation:
Vasomotor nerve fibers of the sympathetic nervous system innervate the smooth muscle of
the tunica media to regulate vessel diameter.
6. What is the outermost layer of a blood vessel wall, composed largely of collagen
and elastic fibers?
A) Tunica media
B) Tunica intima
, C) Tunica externa
D) Internal elastic lamina
Answer: C) Tunica externa Explanation: The tunica externa (or tunica adventitia) is the
outer protective sheath made of collagen fibers that anchor the vessel to surrounding
organs.
7. What is the name of the system of tiny blood vessels that nourish the outer walls
of large blood vessels?
A) Thoroughfare channels
B) Anastomoses
C) Vasa vasorum
D) Sinusoids
Answer: C) Vasa vasorum Explanation: Large blood vessels have walls too thick for
nutrients to diffuse through from the lumen; the vasa vasorum ("vessels of vessels") supply
the outer tunics.
8. In which type of blood vessel is the tunica media typically the thickest layer
relative to vessel size?
A) Large veins
B) Capillaries
C) Muscular arteries
D) Venules
2026 | Module 3: Cardiovascular System – Blood
Vessels Exam Review |70+ Questions and
Answers Summary |LockDown Browser |Portage
Learning
Module 3: Cardiovascular System – Blood Vessels
This module discusses the structure and function of blood vessels and the circulatory
pathways in the body.
Blood Vessel Types:
o Arteries: Carry blood away from the heart; thick muscular walls.
o Veins: Carry blood toward the heart; thinner walls, often with valves.
o Capillaries: Microscopic vessels for exchange of gases, nutrients, and
wastes.
Blood Pressure: The force exerted by blood on vessel walls, measured in mmHg.
Blood Flow Dynamics: Includes capillary exchange, resistance, and regulation by
neural and hormonal mechanisms.
Clinical Correlations: Hypertension, hypotension, and shock.
Example: Blood pressure readings are used to diagnose and monitor cardiovascular health.
Section 1: Structure of Blood Vessel Walls (Questions 1–10)
1. Which layer of a blood vessel wall is in direct contact with the blood flowing
through the lumen?
A) Tunica externa
B) Tunica media
,C) Tunica intima
D) Tunica adventitia
Answer: C) Tunica intima Explanation: The tunica intima is the innermost layer of a blood
vessel wall, making direct contact with the blood flowing through the lumen.
2. The tunica intima is structurally composed of which tissue types?
A) Simple columnar epithelium resting on skeletal muscle
B) Simple squamous epithelium (endothelium) resting on a thin basement membrane
C) Stratified squamous epithelium backed by dense irregular connective tissue
D) Smooth muscle and elastic fibers
Answer: B) Simple squamous epithelium (endothelium) resting on a thin basement
membrane Explanation: The tunica intima consists of a smooth lining of simple
squamous cells called endothelium, supported by a thin subendothelial layer of loose
connective tissue.
3. Which tunic layer is dominated by smooth muscle and elastic fibers, regulating
vessel diameter?
A) Tunica externa
B) Tunica intima
C) Tunica media
D) Vasa vasorum
Answer: C) Tunica media Explanation: The tunica media is the thick middle layer
composed primarily of circularly arranged smooth muscle cells and sheets of elastic fibers.
,4. Vasoconstriction and vasodilation are mediated by the smooth muscle located in
which layer of the vascular wall?
A) Tunica intima
B) Tunica media
C) Tunica externa
D) Tunica adventitia
Answer: B) Tunica media Explanation: Smooth muscle contraction (vasoconstriction) and
relaxation (vasodilation) are restricted to the tunica media, directly altering blood flow and
blood pressure.
5. Which branch of the nervous system primarily controls the smooth muscle in the
tunica media?
A) Somatic motor division
B) Sympathetic division of the autonomic nervous system
C) Parasympathetic division of the autonomic nervous system
D) Central nervous system somatic sensory fibers
Answer: B) Sympathetic division of the autonomic nervous system Explanation:
Vasomotor nerve fibers of the sympathetic nervous system innervate the smooth muscle of
the tunica media to regulate vessel diameter.
6. What is the outermost layer of a blood vessel wall, composed largely of collagen
and elastic fibers?
A) Tunica media
B) Tunica intima
, C) Tunica externa
D) Internal elastic lamina
Answer: C) Tunica externa Explanation: The tunica externa (or tunica adventitia) is the
outer protective sheath made of collagen fibers that anchor the vessel to surrounding
organs.
7. What is the name of the system of tiny blood vessels that nourish the outer walls
of large blood vessels?
A) Thoroughfare channels
B) Anastomoses
C) Vasa vasorum
D) Sinusoids
Answer: C) Vasa vasorum Explanation: Large blood vessels have walls too thick for
nutrients to diffuse through from the lumen; the vasa vasorum ("vessels of vessels") supply
the outer tunics.
8. In which type of blood vessel is the tunica media typically the thickest layer
relative to vessel size?
A) Large veins
B) Capillaries
C) Muscular arteries
D) Venules
