BIOL 252 Human Anatomy & Physiology
II w/Lab Module 3 Exam: The
Cardiovascular System - Blood Vessels
and Circulation 100 Questions with
Correct Answers and Expert Rationales
SECTION A: Overview and Structure of Blood Vessels
(Questions 1-25)
1. The layer of the blood vessel wall that is in direct contact
with blood is the:
A) Tunica externa
B) Tunica media
C) Tunica intima
D) Adventitia
Correct Answer: C) Tunica intima
Expert Rationale: The tunica intima (interna) is the innermost layer
of the blood vessel wall, composed of endothelium (simple
squamous epithelium) in direct contact with blood. It provides a
smooth surface to reduce friction and prevent clot formation .
2. The tunica media of a blood vessel is composed primarily
of:
,A) Endothelium
B) Smooth muscle and elastic fibers
C) Connective tissue
D) Skeletal muscle
Correct Answer: B) Smooth muscle and elastic fibers
Expert Rationale: The tunica media is the middle layer composed of
smooth muscle and elastic fibers. It is responsible for
vasoconstriction and vasodilation, regulating blood pressure and
flow .
3. The tunica externa (adventitia) is composed of:
A) Simple squamous epithelium
B) Smooth muscle
C) Connective tissue
D) Elastic fibers only
Correct Answer: C) Connective tissue
Expert Rationale: The tunica externa (adventitia) is the outermost
layer composed of connective tissue (collagen and elastic fibers). It
provides structural support and anchors vessels to surrounding
tissues .
4. Which type of blood vessel has the thickest tunica media?
A) Veins
B) Capillaries
,C) Arteries
D) Venules
Correct Answer: C) Arteries
Expert Rationale: Arteries have the thickest tunica media to
withstand and regulate high pressure. The thick smooth muscle
layer allows for significant vasoconstriction and vasodilation .
5. Which type of blood vessel has valves to prevent backflow
of blood?
A) Arteries
B) Capillaries
C) Veins
D) Arterioles
Correct Answer: C) Veins
Expert Rationale: Veins contain valves (especially in the limbs) that
prevent backflow of blood due to low venous pressure and the
effects of gravity. These valves are essential for venous return .
6. The largest artery in the body is the:
A) Pulmonary artery
B) Aorta
C) Carotid artery
D) Femoral artery
Correct Answer: B) Aorta
, Expert Rationale: The aorta is the largest artery in the body,
originating from the left ventricle. It distributes oxygenated blood
to all systemic circulation through its branches .
7. The smallest branches of the arterial system are the:
A) Arterioles
B) Metarterioles
C) Capillaries
D) Venules
Correct Answer: A) Arterioles
Expert Rationale: Arterioles are the smallest branches of the
arterial system, regulating blood flow into capillary beds through
vasoconstriction and vasodilation. They are the primary site of
peripheral resistance .
8. The smallest blood vessels where exchange of gases and
nutrients occurs are the:
A) Arteries
B) Veins
C) Capillaries
D) Venules
Correct Answer: C) Capillaries
Expert Rationale: Capillaries are the smallest blood vessels and the
site of exchange between blood and tissues. Their thin walls (single
II w/Lab Module 3 Exam: The
Cardiovascular System - Blood Vessels
and Circulation 100 Questions with
Correct Answers and Expert Rationales
SECTION A: Overview and Structure of Blood Vessels
(Questions 1-25)
1. The layer of the blood vessel wall that is in direct contact
with blood is the:
A) Tunica externa
B) Tunica media
C) Tunica intima
D) Adventitia
Correct Answer: C) Tunica intima
Expert Rationale: The tunica intima (interna) is the innermost layer
of the blood vessel wall, composed of endothelium (simple
squamous epithelium) in direct contact with blood. It provides a
smooth surface to reduce friction and prevent clot formation .
2. The tunica media of a blood vessel is composed primarily
of:
,A) Endothelium
B) Smooth muscle and elastic fibers
C) Connective tissue
D) Skeletal muscle
Correct Answer: B) Smooth muscle and elastic fibers
Expert Rationale: The tunica media is the middle layer composed of
smooth muscle and elastic fibers. It is responsible for
vasoconstriction and vasodilation, regulating blood pressure and
flow .
3. The tunica externa (adventitia) is composed of:
A) Simple squamous epithelium
B) Smooth muscle
C) Connective tissue
D) Elastic fibers only
Correct Answer: C) Connective tissue
Expert Rationale: The tunica externa (adventitia) is the outermost
layer composed of connective tissue (collagen and elastic fibers). It
provides structural support and anchors vessels to surrounding
tissues .
4. Which type of blood vessel has the thickest tunica media?
A) Veins
B) Capillaries
,C) Arteries
D) Venules
Correct Answer: C) Arteries
Expert Rationale: Arteries have the thickest tunica media to
withstand and regulate high pressure. The thick smooth muscle
layer allows for significant vasoconstriction and vasodilation .
5. Which type of blood vessel has valves to prevent backflow
of blood?
A) Arteries
B) Capillaries
C) Veins
D) Arterioles
Correct Answer: C) Veins
Expert Rationale: Veins contain valves (especially in the limbs) that
prevent backflow of blood due to low venous pressure and the
effects of gravity. These valves are essential for venous return .
6. The largest artery in the body is the:
A) Pulmonary artery
B) Aorta
C) Carotid artery
D) Femoral artery
Correct Answer: B) Aorta
, Expert Rationale: The aorta is the largest artery in the body,
originating from the left ventricle. It distributes oxygenated blood
to all systemic circulation through its branches .
7. The smallest branches of the arterial system are the:
A) Arterioles
B) Metarterioles
C) Capillaries
D) Venules
Correct Answer: A) Arterioles
Expert Rationale: Arterioles are the smallest branches of the
arterial system, regulating blood flow into capillary beds through
vasoconstriction and vasodilation. They are the primary site of
peripheral resistance .
8. The smallest blood vessels where exchange of gases and
nutrients occurs are the:
A) Arteries
B) Veins
C) Capillaries
D) Venules
Correct Answer: C) Capillaries
Expert Rationale: Capillaries are the smallest blood vessels and the
site of exchange between blood and tissues. Their thin walls (single
