Section 12.1 Your Cardiovascular System
Your Cardiovascular System
I can…
Describe the main functions of the
cardiovascular system.
Explain the pathway of blood through the heart.
Identify three types of blood vessels and the
four components of blood.
Slide 1 of 31
Section 12.1 Your Cardiovascular System
Fact or Fiction: Blood is blue in color when it is not
carrying oxygen.
Fiction: Blood is bright red when it is carrying oxygen
and dark red when it is not. Veins appear blue in some
people because of the way light reflects from their skin.
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Section 12.1 Your Cardiovascular System
Functions of the Cardiovascular System
• The main functions of the cardiovascular system
include
• delivering materials to cells
• carrying wastes away
• In addition, blood contains cells that fight disease.
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Section 12.1 Your Cardiovascular System
The Heart
• Think of your cardiovascular system as a network of
blood vessels with two major loops.
• The first loop leads from your heart to your lungs.
• The second loop circles through to the rest of
your body.
• Each time the heart beats, strong cardiac muscles
push blood through the blood vessels.
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Section 12.1 Your Cardiovascular System
Structure of the Heart
• Each side of the heart has two chambers: an upper
chamber called an atrium (plural, atria) and a lower
chamber, or ventricle.
• The atria receive blood entering the heart.
• Blood flows from the atria to the ventricles, which
pump blood out of the heart.
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Section 12.1 Your Cardiovascular System
The Heart
1)
2)
3)
4)
Major vessel from
upper body to heart
1
5
Vessels from
lung to heart
2
Right Atrium
The right atrium
receives blood from 3
the body that is low
in oxygen and high
in carbon dioxide.
4
Right Ventricle
The right ventricle
pumps oxygen-poor
blood to the lungs.
6
5)
The aorta carries
blood from the left
ventricle to the body.
6)
Vessel from
heart to lungs
7)
Vessels from
lung to heart
8)
Left Atrium
Oxygen-rich blood
is carried from the
lungs to the left
atrium.
9)
Left Ventricle
The left ventricle
pumps oxygen-rich
blood from the heart.
7
8
9
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Section 12.1 Your Cardiovascular System
Your Heartbeat
• The action of the heart has two main phases.
• In the first phase, the heart relaxes and the atria
fill with blood.
• In the second phase, the heart contracts and
pumps blood.
• Average heart rate varies from one person to the
next and from one situation to the next.
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Section 12.1 Your Cardiovascular System
Blood Vessels
• Your heart pumps blood through an extensive
network of blood vessels.
• The three main types of blood vessels in your
body are
• Arteries- carry blood away from the heart
• Capillaries- the smallest arteries
• As blood flows through the capillaries, oxygen
and dissolved nutrients diffuse through the
capillary walls and into your body’s cells.
• Veins- large, thin-walled blood vessels that carry
blood to the heart
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Section 12.1 Your Cardiovascular System
Blood Vessels
Artery
Artery
Cross Section
Smooth muscle
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Section 12.1 Your Cardiovascular System
Blood Vessels
Capillary
Vein
Capillary
Cross Section
Vein Cross Section
Layer of cells
Smooth muscle
Connective tissue
Single layer of cells
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Section 12.1 Your Cardiovascular System
Vocabulary
atrium
ventricle
pacemaker
An upper chamber of the heart that receives
blood from the rest of the body.
A lower chamber of the heart that pumps blood
out of the heart.
A small group of cells in the wall of the right
atrium that controls the rate at which the heart
muscles contract.
artery
A thick-walled blood vessel that carries blood
away from the heart.
capillary
The smallest type of blood vessel in the body.
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Section 12.1 Your Cardiovascular System
Vocabulary
vein
blood pressure
hypertension
plasma
red blood cell
A large, thin-walled blood vessel that carries
blood to the heart.
The force with which blood pushes against the
walls of blood vessels.
Blood pressure that is consistently 140/90 or
greater.
A liquid that makes up about 55 percent of the
blood.
A hemoglobin-containing cell that carries oxygen
from the lungs to other parts of the body.
Slide 12 of 31
Section 12.1 Your Cardiovascular System
Vocabulary
white blood cell
platelet
A cell that helps protect the body from diseases
and foreign substances.
A cell fragment that plays an important role in
the blood clotting process.
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