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BIO 202L LAB 11 WORKSHEET CIRCULATORY SYSTEM
2026/2027 | Blood Vessels & Hemodynamics |
Comprehensive Lab Assessment | Pass Guaranteed - A+
Graded
Section 1: Blood Vessel Structure & Histology (Q1-15)
Q1. The tunica intima of a blood vessel is composed of which tissue layers? A. Simple
squamous epithelium, basement membrane, and loose connective tissue B. Simple
cuboidal epithelium and reticular fibers C. Simple squamous endothelium, basement
membrane, and internal elastic lamina [CORRECT] D. Stratified squamous epithelium
and dense irregular connective tissue
Rationale: The tunica intima consists of a simple squamous endothelium resting on a
basement membrane, often with an internal elastic lamina in arteries. This layer
provides a smooth lining that minimizes blood clot formation and regulates vessel
permeability.
Correct Answer: C
Q2. Which component of the tunica media is primarily responsible for
vasoconstriction and vasodilation? A. Collagen fibers B. Smooth muscle cells
[CORRECT] C. Elastic fibers D. Fibroblasts
Rationale: The tunica media contains concentric layers of smooth muscle cells that
contract (vasoconstriction) or relax (vasodilation) to regulate vessel diameter and
blood flow distribution.
Correct Answer: B
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Q3. A histology slide shows a vessel with a thick tunica media containing multiple
layers of smooth muscle, a prominent internal elastic lamina, and a round lumen. The
adjacent vessel has a thinner wall, larger irregular lumen, and contains visible valves.
The first vessel is: A. A large vein B. A venule C. A muscular artery [CORRECT] D. A
continuous capillary
Rationale: The thick tunica media with smooth muscle, prominent internal elastic
lamina, and round lumen are characteristic of a muscular (distributing) artery,
whereas the thin-walled, valved vessel with an irregular lumen is a vein.
Correct Answer: C
Q4. Elastic (conducting) arteries such as the aorta contain abundant elastic fibers in
the tunica media that function to: A. Prevent backflow of blood B. Store kinetic
energy during systole and release it during diastole to maintain continuous blood
flow [CORRECT] C. Filter blood through fenestrations D. Produce vasoconstriction in
response to sympathetic stimulation
Rationale: Elastic arteries act as a pressure reservoir (Windkessel effect); their elastic
fibers stretch during ventricular systole to store energy and recoil during diastole to
propel blood forward, maintaining continuous perfusion.
Correct Answer: B
Q5. A researcher observes capillaries in the kidney glomerulus that contain pores
(fenestrations) but lack a complete basement membrane diaphragm. These
capillaries are classified as: A. Continuous capillaries B. Fenestrated capillaries
[CORRECT] C. Sinusoid capillaries D. Lymphatic capillaries
Rationale: Fenestrated capillaries contain pores (fenestrations) that permit rapid
exchange of fluids and small solutes, making them ideal for organs involved in
filtration and absorption such as the kidney glomerulus and intestinal villi.
, 3
Correct Answer: B
Q6. Sinusoid capillaries are found in which of the following organs? A. Skeletal
muscle and brain B. Kidney glomerulus and small intestine C. Liver, spleen, bone
marrow, and anterior pituitary [CORRECT] D. Lung alveoli and skin
Rationale: Sinusoid capillaries have large, irregular lumens with gaps between
endothelial cells and an incomplete basement membrane, allowing passage of large
molecules and blood cells in organs like the liver, spleen, and bone marrow.
Correct Answer: C
Q7. A student examining a histology slide notes a vessel with the thickest wall
relative to lumen diameter, a well-defined internal elastic lamina, and approximately
40 layers of smooth muscle. This vessel is most likely: A. The vena cava B. A large
elastic artery C. A muscular artery [CORRECT] D. A medium-sized vein
Rationale: Muscular (distributing) arteries have the thickest tunica media relative to
lumen size, with prominent smooth muscle layers and a distinct internal elastic
lamina, distinguishing them from elastic arteries (more elastic fibers) and veins
(thinner walls).
Correct Answer: C
Q8. In a histological preparation of the liver, a student observes wide, irregular
vascular channels lined by macrophages and hepatocytes with direct contact to
blood. These structures represent: A. Postcapillary venules B. Fenestrated capillaries
C. Sinusoids [CORRECT] D. Lymphatic vessels
Rationale: Liver sinusoids are specialized, wide capillary-like channels with
discontinuous endothelium and gaps that allow plasma to directly contact
hepatocytes and permit phagocytic Kupffer cells to monitor blood contents.
BIO 202L LAB 11 WORKSHEET CIRCULATORY SYSTEM
2026/2027 | Blood Vessels & Hemodynamics |
Comprehensive Lab Assessment | Pass Guaranteed - A+
Graded
Section 1: Blood Vessel Structure & Histology (Q1-15)
Q1. The tunica intima of a blood vessel is composed of which tissue layers? A. Simple
squamous epithelium, basement membrane, and loose connective tissue B. Simple
cuboidal epithelium and reticular fibers C. Simple squamous endothelium, basement
membrane, and internal elastic lamina [CORRECT] D. Stratified squamous epithelium
and dense irregular connective tissue
Rationale: The tunica intima consists of a simple squamous endothelium resting on a
basement membrane, often with an internal elastic lamina in arteries. This layer
provides a smooth lining that minimizes blood clot formation and regulates vessel
permeability.
Correct Answer: C
Q2. Which component of the tunica media is primarily responsible for
vasoconstriction and vasodilation? A. Collagen fibers B. Smooth muscle cells
[CORRECT] C. Elastic fibers D. Fibroblasts
Rationale: The tunica media contains concentric layers of smooth muscle cells that
contract (vasoconstriction) or relax (vasodilation) to regulate vessel diameter and
blood flow distribution.
Correct Answer: B
,2
Q3. A histology slide shows a vessel with a thick tunica media containing multiple
layers of smooth muscle, a prominent internal elastic lamina, and a round lumen. The
adjacent vessel has a thinner wall, larger irregular lumen, and contains visible valves.
The first vessel is: A. A large vein B. A venule C. A muscular artery [CORRECT] D. A
continuous capillary
Rationale: The thick tunica media with smooth muscle, prominent internal elastic
lamina, and round lumen are characteristic of a muscular (distributing) artery,
whereas the thin-walled, valved vessel with an irregular lumen is a vein.
Correct Answer: C
Q4. Elastic (conducting) arteries such as the aorta contain abundant elastic fibers in
the tunica media that function to: A. Prevent backflow of blood B. Store kinetic
energy during systole and release it during diastole to maintain continuous blood
flow [CORRECT] C. Filter blood through fenestrations D. Produce vasoconstriction in
response to sympathetic stimulation
Rationale: Elastic arteries act as a pressure reservoir (Windkessel effect); their elastic
fibers stretch during ventricular systole to store energy and recoil during diastole to
propel blood forward, maintaining continuous perfusion.
Correct Answer: B
Q5. A researcher observes capillaries in the kidney glomerulus that contain pores
(fenestrations) but lack a complete basement membrane diaphragm. These
capillaries are classified as: A. Continuous capillaries B. Fenestrated capillaries
[CORRECT] C. Sinusoid capillaries D. Lymphatic capillaries
Rationale: Fenestrated capillaries contain pores (fenestrations) that permit rapid
exchange of fluids and small solutes, making them ideal for organs involved in
filtration and absorption such as the kidney glomerulus and intestinal villi.
, 3
Correct Answer: B
Q6. Sinusoid capillaries are found in which of the following organs? A. Skeletal
muscle and brain B. Kidney glomerulus and small intestine C. Liver, spleen, bone
marrow, and anterior pituitary [CORRECT] D. Lung alveoli and skin
Rationale: Sinusoid capillaries have large, irregular lumens with gaps between
endothelial cells and an incomplete basement membrane, allowing passage of large
molecules and blood cells in organs like the liver, spleen, and bone marrow.
Correct Answer: C
Q7. A student examining a histology slide notes a vessel with the thickest wall
relative to lumen diameter, a well-defined internal elastic lamina, and approximately
40 layers of smooth muscle. This vessel is most likely: A. The vena cava B. A large
elastic artery C. A muscular artery [CORRECT] D. A medium-sized vein
Rationale: Muscular (distributing) arteries have the thickest tunica media relative to
lumen size, with prominent smooth muscle layers and a distinct internal elastic
lamina, distinguishing them from elastic arteries (more elastic fibers) and veins
(thinner walls).
Correct Answer: C
Q8. In a histological preparation of the liver, a student observes wide, irregular
vascular channels lined by macrophages and hepatocytes with direct contact to
blood. These structures represent: A. Postcapillary venules B. Fenestrated capillaries
C. Sinusoids [CORRECT] D. Lymphatic vessels
Rationale: Liver sinusoids are specialized, wide capillary-like channels with
discontinuous endothelium and gaps that allow plasma to directly contact
hepatocytes and permit phagocytic Kupffer cells to monitor blood contents.
