Transcript Chapter 17, Section 1 The Body’s Transportation System

Chapter 17, Section 1
The Body’s
Transportation System
Monday, March 15, 2010
Pages 536 -- 542
Objectives
• Describe the function of the
cardiovascular system.
• Describe the structure of the heart and
explain its function.
• Describe the origin of the heartbeat and
why the heart rate changes during
exercise.
• Trace the path taken by blood through the
circulatory system.
Vocabulary Words
• Cardiovascular
system
• Heart
• Atrium
• Ventricle
• Valve
•
•
•
•
•
Pacemaker
Artery
Capillary
Vein
Aorta
The Cardiovascular System
• Also known as the Circulatory System.
• Made up of:
• Heart
• Blood vessels
• Blood
• Carries needed substances to cells and
carries waste products away from cells.
Movement of Materials
• Substances that need to get from one part
of the body to another are carried by the
blood.
• Wastes are also picked up and expelled
through exhalation.
• Transports cells that attack diseasecausing microorganisms.
Cardiovascular System
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• Blood vessels reach the
entire body.
• RED represents arteries.
Arteries are oxygen-rich.
• BLUE represents veins.
Veins are oxygen-poor.
The Heart
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• Hollow, muscular
organ.
• Pumps blood
throughout the body.
• Size of your fist.
• Located in the center
of your chest.
The Heart’s Structure
• The heart has two sides: right and left.
• Each side is completely separated from
each other by a wall of tissue.
• Each side has two compartments called
chambers.
• There is an upper and lower chamber on
each side.
– The upper chambers are called atria (atrium singular).
– The lower chambers are called ventricles.
The Heart
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The Atrium
• The atria are
separated from the
ventricles by
valves.
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– Valves are flaps of
tissue that
prevents the
backflow of blood.
• The atria receive
blood that comes
into the heart.
The Ventricles
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• Located in the
lower portion
of the heart.
• Pumps blood
out of the
heart.
How The Heart Works
• Two main phases.
– Heart muscles relax and the atria fill with
blood.
– The atria contract and fill the ventricles and
the ventricles contract to pump blood
forward. (The sound of your heartbeat is
made by this pumping phase.)
• This process happens in less than a
second.
The Valve
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• It is a flap of
tissue that
prevents the
backflow of
blood.
Pacemaker
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decompressor
are needed to see this picture.
• A group of cells
located in the
right atrium.
• Constantly
receives
messages about
the body’s
oxygen needs.
• Heart rate is
adjusted to match
needs.
Two Loops
• Body has three kinds of blood vessels:
– ARTERIES -- blood vessels that carry
blood away from the heart.
– CAPILLARIES -- substances are
exchanged between the blood and body
cells.
– VEINS -- blood vessels that carry blood
back to the heart
Two Loops -- cont’d
• Blood flows through the body in a figure
eight pattern.
• The heart is at the center where the two
loops cross.
Loop One
• Blood travels from
the heart to the
lungs and then back
to the heart.
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– Blood from the body
flowing into the right
atrium is oxygenpoor (low oxygen
and high carbon
dioxide)
– Oxygen-poor blood
is dark red.
Loop One -- cont’d
• Flow of blood:
– Right atrium ---> right ventricle ---> arteries
towards the lungs ---> capillaries close to
the lungs ---> picks up oxygen from the
lungs (the blood is now oxygen-rich) --->
carbon dioxide moves from blood into the
lungs (and carbon dioxide-poor) ---> blood
(bright red now) flows to the left side to be
pumped through Loop Two.
Loop Two
• Blood flows to the body and back.
– Left atrium fills with oxygen-rich blood
coming from the lungs ---> left ventricle --> aorta (largest artery in the body) --->
branching arteries and tiny capillaries in
different parts of the body ---> oxygen
moves out of the blood and into the body
cells ---> carbon dioxide passes from the
body cells into the blood ---> blood flows
back to the right atrium through veins.
Homework
• Workbook 17.1 (3/17)
• Vocabulary quiz 17.1 (3/17)