BIOS 255 ANATOMY & PHYSIOLOGY III — EXAM 2
CHAMBERLAIN 2026/2027 COMPLETE (150) CURRENT
TESTING QUESTIONS AND CORRECT ANSWERS WITH
DETAILED RATIONALES.
BIOS
Prepare effectively for the BIOS 255 Anatomy & Physiology III Exam 2 at Chamberlain
with this focused study resource. It supports review of advanced anatomy and
physiology concepts, body systems, physiological processes, homeostasis, and key
relationships between structure and function. Use the material to reinforce your
understanding, review high-yield topics, and identify areas that may require additional
study. This resource is suited for Chamberlain nursing students, BIOS 255 learners,
and candidates preparing for Exam 2.
MULTIPLE CHOICE.
SECTION 1: BLOOD VESSEL STRUCTURE & CLASSIFICATION (Questions 1–
25)
1. Which blood vessel class is the LARGEST and characterized by having a
thick tunica media dominated by elastic laminae?
• A. Muscular arteries
• B. Elastic arteries (conducting arteries)
• C. Arterioles
• D. Capillaries
Answer: B. Elastic arteries (conducting arteries)
Rationale: Elastic arteries (conducting arteries) are the largest blood
vessels, including the aorta and its major branches. They have a thick
tunica media dominated by elastic laminae, which allows them to stretch
and recoil to accommodate the pressure changes from the heart.
2. What is the innermost layer of a blood vessel called?
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• A. Tunica externa
• B. Tunica intima
• C. Tunica media
• D. Tunica adventitia
Answer: B. Tunica intima
Rationale: The tunica intima is the innermost layer of a blood vessel. It
consists of a simple squamous epithelium called the endothelium, which
is in direct contact with the blood.
3. Which layer of a blood vessel is thickest in arteries and contains
smooth muscle and elastic fibers?
• A. Tunica intima
• B. Tunica media
• C. Tunica externa
• D. Endothelium
Answer: B. Tunica media
Rationale: The tunica media is the middle layer of a blood vessel and is
thickest in arteries. It contains smooth muscle, collagen, and elastic
fibers, allowing for vasoconstriction and vasodilation. This layer is
responsible for maintaining blood pressure and flow.
4. Veins differ from arteries in which of the following ways?
• A. Veins have thicker tunica media than arteries
• B. Veins contain valves to prevent backflow
• C. Veins carry oxygenated blood only
• D. Veins have more elastic tissue than arteries
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Answer: B. Veins contain valves to prevent backflow
Rationale: Veins contain valves that prevent the backflow of blood,
especially in the lower extremities where blood must travel against
gravity. Arteries have thicker tunica media to handle high pressure, while
veins have thinner walls and larger lumens.
5. Which blood vessels are responsible for the exchange of gases,
nutrients, and wastes between blood and tissues?
• A. Arteries
• B. Arterioles
• C. Capillaries
• D. Venules
Answer: C. Capillaries
Rationale: Capillaries are the smallest blood vessels and are the sites of
exchange between blood and interstitial fluid. Their thin walls (only
endothelium) allow for the diffusion of oxygen, carbon dioxide, nutrients,
and wastes.
6. The tunica externa (tunica adventitia) is composed primarily of:
• A. Endothelial cells
• B. Smooth muscle
• C. Collagen fibers
• D. Elastic fibers
Answer: C. Collagen fibers
Rationale: The tunica externa (adventitia) is the outermost layer of a blood
vessel. It is composed primarily of collagen fibers that provide structural
support and protection. This layer anchors the vessel to surrounding
tissues.
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7. Which of the following is NOT considered a type of blood vessel?
• A. Artery
• B. Vein
• C. Lymphatic vessel
• D. Capillary
Answer: C. Lymphatic vessel
Rationale: Lymphatic vessels are part of the lymphatic system, not the
cardiovascular system. The three main types of blood vessels are
arteries, veins, and capillaries.
8. Which statement correctly describes the relationship between arteries
and veins?
• A. Arteries always carry oxygenated blood; veins always carry
deoxygenated blood
• B. Arteries carry blood away from the heart; veins carry blood
toward the heart
• C. Arteries have valves; veins do not
• D. Arteries have thinner walls than veins
Answer: B. Arteries carry blood away from the heart; veins carry blood
toward the heart
Rationale: Arteries carry blood away from the heart (with the exception of
the pulmonary arteries, which carry deoxygenated blood to the lungs).
Veins carry blood toward the heart (with the exception of the pulmonary
veins, which carry oxygenated blood from the lungs). Arteries have thicker
walls and no valves; veins have thinner walls and valves.
9. The largest vein in the body is the: