Download Unit 3 Lesson 4

Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and
Circulate Blood?
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
• The heart is a muscular organ that pumps blood
throughout the body. It contracts in two phases.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
When the top part relaxes, it fills with blood. When
it contracts, the top part squeezes blood to the
lower part.
• When the lower part contracts, it squeezes blood
from the heart into vessels and all parts of the
body.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
• Blood it carries nutrients and other substances to the
cells.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
• Blood is made up of a clear liquid called plasma
and small structures called blood cells.
• Red blood cells carry oxygen throughout the
body.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
White blood cells help fight disease.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
• Platelets stop bleeding by forming clots.
• Plasma carries nutrients throughout the body.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
2-Blood
your body.
vessels carry the blood to every part of
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Blood vessels
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Beat It
• Arteries carry blood away from the heart.
• Veins bring blood back to the heart from the
lungs and the body.
• Oxygen, nutrients, and carbon dioxide pass
through capillaries, or tiny vessels with very thin
walls, to parts of the body and into the blood.
• The heart, vessels, and blood are all part of the
circulatory system.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Breathe In, Breathe Out
• Organs in the respiratory system bring in oxygen
and release carbon dioxide.
• Air enters the body through the nose or mouth
and flows through a tube in the throat called the
trachea.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Breathe In, Breathe Out
• Lungs, the main organs of the respiratory system,
are spongy organs that expand to fill with air.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Breathe In, Breathe Out
• The trachea branches into two smaller tubes
called bronchi.
• Bronchi branch into many bronchioles in the
lungs.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Breathe In, Breathe Out
Tiny sacs called alveoli are attached to bronchioles.
They inflate and deflate as you inhale and exhale.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Breathe In, Breathe Out
• Red blood cells in the alveoli absorb oxygen.
Identify the blood vessels and alveoli.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Asthma Attack
Constricted Airways
• Asthma is an illness that makes it hard for a
person to breathe.
• During an asthma attack, bronchi become swollen,
making airways smaller. This makes it much
harder to get air in and out of the lungs.
Copyright © Houghton Mifflin Harcourt Publishing Company
Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Asthma Attack
• Why is it more difficult to breathe during an
asthma attack?
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Asthma Attack
Triggers
• The exact causes of asthma aren’t known.
• Some people are born with asthma, while for
other people, smoke, air pollution, and allergies
can trigger an asthma attack.
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Unit 3 Lesson 4 How Do Our Bodies Move, Breathe, and Circulate Blood?
Asthma Attack
Management
• People can try to avoid asthma triggers; however,
people can’t always avoid pollen or air pollution.
• A doctor can prescribe an inhaler, a device that
delivers medication to the lungs. The inhaler
releases a mist that can help open up airways.
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