68W MODULE 5 questions and answers A+ Grade 2026\2027
Shock is the circulatory system's failure to provide sufficient blood and oxygen to all the body's tissues.
Which of the answers is NOT a major type of shock?
A) Hypovolemic
B) Hemorrhagic
C) Hypervolemic
D) Cardiogenic
- correct answer Answer: C
Explanation: A) INCORRECT. Hypovolemic shock is one of the three major types of shock and results
from blood or fluid loss.
B) INCORRECT. Hemorrhagic shock is one of the three major types of shock and results from blood loss.
C) CORRECT. Hypervolemic shock is not one of the three major types of shock.
D) INCORRECT. Cardiogenic shock is one of the three major types of shock and is brought on by
inadequate pumping action of the heart.
Page Ref: 671-672
Objective: 25.1
Which of the following vessels has the thickest muscular walls that allow constriction and dilation?
A) Arteries
B) Capillaries
C) Veins
D) Lymphatic vessels
- correct answer Answer: A
Explanation: A) CORRECT. Arteries have the thickest muscular walls to allow for vasoconstriction and
vasodilation.
B) INCORRECT. Capillaries are thin walled vessels without muscles.
,C) INCORRECT. Veins have muscular walls, but are not as thick as arteries.
D) INCORRECT. The lymphatic vessels are transport vessels without smooth muscle.
Page Ref: 655
Objective: 25.2
Which of the following types of vessels have valves to maintain one-way blood flow?
A) Arteries
B) Capillaries
C) Veins
D) Arterioles
- correct answer Answer: C
Explanation: A) INCORRECT. Arteries do not have valves to maintain one-way blood flow.
B) INCORRECT. Capillaries do not have valves to maintain one-way blood flow.
C) CORRECT. Veins have valves in them to maintain the one-way blood flow back towards the heart.
D) INCORRECT. Arterioles do not have valves to maintain one-way blood flow.
Page Ref: 655
Objective: 25.2
Which of the following BEST describes the function of blood?
A) It is a life-giving liquid that supports all the body's functions to maintain hypoperfusion.
B) It clots, flows, transports, protects, and excretes on a daily basis.
C) It transports gases along with nutrients, aids in excretion, and provides protection and regulation.
D) It flows from the heart with the vital gases and nutrients to maintain lack of perfusion.
- correct answer Answer: C
Explanation: A) INCORRECT. Hypoperfusion is the lack of adequate perfusion, or the lack of perfusion in
a body, and the blood does not try to maintain this.
B) INCORRECT. Blood is not intended to clot on a regular basis during injury.
C) CORRECT. Blood transports gases like oxygen along with nutrients, aids in excretion of waste products
(like CO2), and provides protection and regulation.
D) INCORRECT. Blood flows throughout the body and tries to maintain perfusion, not lack of perfusion.
,Page Ref: 656-657
Objective: 25.2
Which of the following is NOT part of the circulatory system?
A) Heart
B) Brain
C) Blood vessels
D) Blood
- correct answer Answer: B
Explanation: A) INCORRECT. The heart is part of the circulatory system.
B) CORRECT. The brain is part of the nervous system and not a part of the circulatory system.
C) INCORRECT. The blood vessels are part of the circulatory system.
D) INCORRECT. Blood is part of the circulatory system.
Page Ref: 654
Objective: 25.2
In which of the following vessels does the vital exchange take place and also has the thinnest walls
through which oxygen, nutrients, and wastes can pass?
A) Capillaries
B) Microvenules
C) Arterioles
D) Veins
- correct answer Answer: A
Explanation: A) CORRECT. The smallest vessels where gas exchange can occur are in the capillaries.
B) INCORRECT. A microvenule would imply a smaller venule which would still have too thick of a wall for
gas exchange.
C) INCORRECT. The arterioles are smaller arteries, but their walls are too thick and musculature, which
prevents gas exchange from occurring.
D) INCORRECT. The veins are larger, but their walls are too thick and musculature, which prevents gas
exchange from occurring.
Page Ref: 655
, Objective: 25.2
Which of the following BEST describes the delivery of oxygen and nutrients at the body's cellular level?
A) Hydrostatic pressure
B) Perfusion
C) Osmosis
D) Circulation
- correct answer Answer: B
Explanation: A) INCORRECT. Hydrostatic pressure is the pressure exerted by water on a system.
B) CORRECT. The adequate circulation of blood throughout the body, which fills the capillaries and
supplies the cells and tissues with oxygen and nutrients, is called perfusion.
C) INCORRECT. Osmosis is the tendency of water or another fluid to travel through a semipermeable
membrane.
D) INCORRECT. Circulation of the blood is throughout the body but does not imply the delivery of
nutrients and oxygen at the cellular level.
Page Ref: 653-654
Objective: 25.3
Which of the following blood vessels CANNOT stop bleeding by constricting?
A) Arteries
B) Capillaries
C) Venules
D) Arterioles
- correct answer Answer: B
Explanation: A) INCORRECT. Arteries have smooth muscle that constricts them aiding in the clotting
process.
B) CORRECT. Capillaries do not possess the muscular layer that reflexively constricts the vessel in
response to local injury. For this reason, capillaries continue to bleed until the clotting process is
successful.
C) INCORRECT. Venules have smooth muscle that constricts them aiding in the clotting process.
D) INCORRECT. Arterioles have smooth muscle that constricts them aiding in the clotting process.
Page Ref: 657
Shock is the circulatory system's failure to provide sufficient blood and oxygen to all the body's tissues.
Which of the answers is NOT a major type of shock?
A) Hypovolemic
B) Hemorrhagic
C) Hypervolemic
D) Cardiogenic
- correct answer Answer: C
Explanation: A) INCORRECT. Hypovolemic shock is one of the three major types of shock and results
from blood or fluid loss.
B) INCORRECT. Hemorrhagic shock is one of the three major types of shock and results from blood loss.
C) CORRECT. Hypervolemic shock is not one of the three major types of shock.
D) INCORRECT. Cardiogenic shock is one of the three major types of shock and is brought on by
inadequate pumping action of the heart.
Page Ref: 671-672
Objective: 25.1
Which of the following vessels has the thickest muscular walls that allow constriction and dilation?
A) Arteries
B) Capillaries
C) Veins
D) Lymphatic vessels
- correct answer Answer: A
Explanation: A) CORRECT. Arteries have the thickest muscular walls to allow for vasoconstriction and
vasodilation.
B) INCORRECT. Capillaries are thin walled vessels without muscles.
,C) INCORRECT. Veins have muscular walls, but are not as thick as arteries.
D) INCORRECT. The lymphatic vessels are transport vessels without smooth muscle.
Page Ref: 655
Objective: 25.2
Which of the following types of vessels have valves to maintain one-way blood flow?
A) Arteries
B) Capillaries
C) Veins
D) Arterioles
- correct answer Answer: C
Explanation: A) INCORRECT. Arteries do not have valves to maintain one-way blood flow.
B) INCORRECT. Capillaries do not have valves to maintain one-way blood flow.
C) CORRECT. Veins have valves in them to maintain the one-way blood flow back towards the heart.
D) INCORRECT. Arterioles do not have valves to maintain one-way blood flow.
Page Ref: 655
Objective: 25.2
Which of the following BEST describes the function of blood?
A) It is a life-giving liquid that supports all the body's functions to maintain hypoperfusion.
B) It clots, flows, transports, protects, and excretes on a daily basis.
C) It transports gases along with nutrients, aids in excretion, and provides protection and regulation.
D) It flows from the heart with the vital gases and nutrients to maintain lack of perfusion.
- correct answer Answer: C
Explanation: A) INCORRECT. Hypoperfusion is the lack of adequate perfusion, or the lack of perfusion in
a body, and the blood does not try to maintain this.
B) INCORRECT. Blood is not intended to clot on a regular basis during injury.
C) CORRECT. Blood transports gases like oxygen along with nutrients, aids in excretion of waste products
(like CO2), and provides protection and regulation.
D) INCORRECT. Blood flows throughout the body and tries to maintain perfusion, not lack of perfusion.
,Page Ref: 656-657
Objective: 25.2
Which of the following is NOT part of the circulatory system?
A) Heart
B) Brain
C) Blood vessels
D) Blood
- correct answer Answer: B
Explanation: A) INCORRECT. The heart is part of the circulatory system.
B) CORRECT. The brain is part of the nervous system and not a part of the circulatory system.
C) INCORRECT. The blood vessels are part of the circulatory system.
D) INCORRECT. Blood is part of the circulatory system.
Page Ref: 654
Objective: 25.2
In which of the following vessels does the vital exchange take place and also has the thinnest walls
through which oxygen, nutrients, and wastes can pass?
A) Capillaries
B) Microvenules
C) Arterioles
D) Veins
- correct answer Answer: A
Explanation: A) CORRECT. The smallest vessels where gas exchange can occur are in the capillaries.
B) INCORRECT. A microvenule would imply a smaller venule which would still have too thick of a wall for
gas exchange.
C) INCORRECT. The arterioles are smaller arteries, but their walls are too thick and musculature, which
prevents gas exchange from occurring.
D) INCORRECT. The veins are larger, but their walls are too thick and musculature, which prevents gas
exchange from occurring.
Page Ref: 655
, Objective: 25.2
Which of the following BEST describes the delivery of oxygen and nutrients at the body's cellular level?
A) Hydrostatic pressure
B) Perfusion
C) Osmosis
D) Circulation
- correct answer Answer: B
Explanation: A) INCORRECT. Hydrostatic pressure is the pressure exerted by water on a system.
B) CORRECT. The adequate circulation of blood throughout the body, which fills the capillaries and
supplies the cells and tissues with oxygen and nutrients, is called perfusion.
C) INCORRECT. Osmosis is the tendency of water or another fluid to travel through a semipermeable
membrane.
D) INCORRECT. Circulation of the blood is throughout the body but does not imply the delivery of
nutrients and oxygen at the cellular level.
Page Ref: 653-654
Objective: 25.3
Which of the following blood vessels CANNOT stop bleeding by constricting?
A) Arteries
B) Capillaries
C) Venules
D) Arterioles
- correct answer Answer: B
Explanation: A) INCORRECT. Arteries have smooth muscle that constricts them aiding in the clotting
process.
B) CORRECT. Capillaries do not possess the muscular layer that reflexively constricts the vessel in
response to local injury. For this reason, capillaries continue to bleed until the clotting process is
successful.
C) INCORRECT. Venules have smooth muscle that constricts them aiding in the clotting process.
D) INCORRECT. Arterioles have smooth muscle that constricts them aiding in the clotting process.
Page Ref: 657
