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Heart and Blood Vessels
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Printed: September 4, 2015
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C HAPTER
Chapter 1. Heart and Blood Vessels
1
Heart and Blood Vessels
Lesson 18.2: True or False
Name___________________ Class______________ Date________
Write true if the statement is true or false if the statement is false.
1.
2.
3.
4.
5.
6.
7.
_______ Blood flows through the heart in two paths
_______ A valve prevents blood from flowing from a ventricle to an atrium.
_______ The systemic circulation includes the right atrium and right ventricle.
_______ The aorta is a large blood vessel that carries blood to the heart.
_______ Veins have thicker walls than arteries.
_______ One way that blood vessels help maintain homeostasis is by dilating or constricting.
_______ The leading cause of cardiovascular disease is atherosclerosis.
Lesson 18.2: Critical Reading
Name___________________ Class______________ Date________
Read this passage based on the text and answer the questions that follow.
The heart is a muscular organ in the chest. It consists mainly of cardiac muscle tissue. It pumps blood by repeated,
rhythmic contractions. This produces the familiar “lub-dub” sound of each heartbeat.
The heart has four chambers. Each chamber is an empty space with muscular walls through which blood can flow.
The top two chambers of the heart are called the left and right atria (atrium, singular). The atria of the heart receive
blood from the body or lungs and pump it into the bottom chambers of the heart. The bottom two chambers of the
heart are called the left and right ventricles. The ventricles receive blood from the atria and pump it out of the heart,
either to the lungs or to the rest of the body.
Flaps of tissue called valves separate the heart’s chambers. Valves keep blood flowing in just one direction through
the heart. For example, a valve at the bottom of the right atrium opens to let blood flow from the right atrium to the
right ventricle. Then the valve closes so the blood can’t flow back into the right atrium.
Blood flows through the heart in two paths. One path is through the right atrium and right ventricle. The right atrium
receives oxygen-poor blood from the body. It pumps the blood into the right ventricle. Then the right ventricle
pumps the blood out of the heart to the lungs. This path through the heart is part of the pulmonary circulation. The
other path is through the left atrium and left ventricle. The left atrium receives oxygen-rich blood from the lungs.
It pumps the blood into the left ventricle. Then the left ventricle pumps the blood out of the heart to the rest of the
body. This path through the heart is part of the systemic circulation.
To move blood through the heart, cardiac muscles must contract in a certain sequence. First the atria must contract,
followed quickly by the ventricles contracting. This series of contractions keeps blood moving continuously through
the heart. Contractions of cardiac muscles aren’t under voluntary control. They are controlled by a cluster of special
cells within the heart, commonly called the pacemaker. These cells send electrical signals to cardiac muscles so they
contract in the correct sequence and with just the right timing.
Questions
1
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1. Describe the four chambers of the heart.
2. Outline the two paths through which blood flows through the heart.
3. Explain the role of the pacemaker in keeping blood flowing through the heart.
Lesson 18.2: Multiple Choice
Name___________________ Class______________ Date________
Circle the letter of the correct choice.
1. Blood in an atrium always flows next to
a.
b.
c.
d.
a ventricle.
an artery.
the lungs.
a vein.
2. In the pulmonary circulation, blood flows through the
a.
b.
c.
d.
right atrium.
right ventricle.
lungs.
all of the above
3. The pacemaker controls the beating of the heart with
a.
b.
c.
d.
enzymes.
hormones.
electrical signals.
valves.
4. Tissues that make up blood vessels include
a.
b.
c.
d.
muscle tissues.
connective tissues.
epithelial tissues.
all of the above
5. Muscular blood vessels that generally carry oxygen-rich blood are
a.
b.
c.
d.
veins.
arteries.
capillaries.
venules.
6. The largest vein in the body is the
a.
b.
c.
d.
aorta.
arteriole.
inferior vena cava.
none of the above
7. Which statement about capillaries is false?
a.
b.
c.
d.
2
The walls of capillaries may be just one cell thick.
Capillaries connect arterioles and venules.
The exchange of substances between cells and the blood takes place across capillary walls.
Capillaries contain valves to prevent the backflow of blood.
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Chapter 1. Heart and Blood Vessels
Lesson 18.2: Matching
Name___________________ Class______________ Date________
Match each definition with the correct term.
Definitions
1.
2.
3.
4.
5.
6.
7.
_______ disorder that occurs when plaque blocks coronary arteries
_______ chamber of the heart that receives oxygen-poor blood from the body
_______ chamber of the heart that pumps blood out of the heart to the rest of the body
_______ chamber of the heart that receives oxygen-rich blood from the lungs
_______ event in which blood supply to the heart is blocked so cardiac muscle cells die
_______ chamber of the heart that pumps blood out of the heart to the lungs
_______ cluster of cells in the heart that control contractions of cardiac muscles
Terms
a.
b.
c.
d.
e.
f.
g.
right atrium
pacemaker
left ventricle
heart attack
right ventricle
left atrium
coronary heart disease
Lesson 18.2: Fill in the Blank
Name___________________ Class______________ Date________
Fill in the blank with the appropriate term.
1.
2.
3.
4.
5.
6.
7.
_____ is a condition in which plaque builds up inside arteries.
A flap of skin that keeps blood flowing in just one direction through the heart is called a(n) _____.
Blood vessels that carry blood away from the heart are referred to as _____.
Blood vessels that carry blood toward the heart are known as _____.
The smallest type of blood vessel is called a(n) _____.
The top two chambers of the heart are named _____.
The bottom two chambers of the heart are named _____.
Lesson 18.2: Critical Writing
Name___________________ Class______________ Date________
Thoroughly answer the question below. Use appropriate academic vocabulary and clear and complete sentences.
Explain how lifestyle choices can reduce the risk of cardiovascular diseases.
3