The Respiratory System
What is the function of the
respiratory system?
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Provides oxygen to
cells
Eliminates carbon
dioxide and water
from the body
http://trc.ucdavis.edu/biosci10v/bis10v/med
ia/ch22/human_respiratory_v2.html
The path of air
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Air enters through the nose. The air is
warmed and cleaned.
From the nose, it passes through the
pharynx or throat.
The epiglottis prevents food from entering
the respiratory tract.
The path of air
The path of air
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Next, it passes through the larynx (voice
box) and into the trachea.
The trachea connects
the pharynx to the
.
lungs.
The trachea divides into bronchus
(bronchi)
The path of air
Larynx or voice box
Path of air
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Each bronchus in the lungs divide into smaller
and smaller tubes (similar to branches of a tree).
At the end of the smallest tubes are tiny
structures called alveoli.
In the alveoli, gases move between the air and
the blood.
Path of Air
http://www.smm.org/
heart/lungs/breathing.
htm
Gas Exchange
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Each alveolus is surrounded by capillaries.
In gas exchange, oxygen passes through
the wall of the alveolus and through the
capillary wall into the blood.
Carbon dioxide and water pass from the
blood into the alveolus
Gas Exchange
http://trc.ucdavis.edu/biosc
i10v/bis10v/media/ch22/co
2_transport.html
Respiratory System
http://bcs.whfre
eman.com/thelif
ewire/content/ch
p48/4802002.ht
ml
Describe the breathing process.
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At the base of the lungs is the diaphragm
(a dome-shaped muscle) which plays an
important role in breathing.
When you inhale, the rib muscles contract
upward and the diaphragm moves
downward.
This causes the chest cavity to be larger
and lets air in.
Describe the breathing process
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When you exhale, the rib muscles and
diaphragm relax and the chest cavity
becomes smaller.
This squeezes the air out of the lungs.
http://trc.ucdavis.edu/biosci10
v/bis10v/media/ch22/breathin
g.html
What other systems work with the
respiratory system?
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Circulatory System: exchanges carbon
dioxide in the blood with oxygen in the
lungs.
Nervous System: breathing is an
involuntary process that is controlled by
the brain.
What other systems work with the
respiratory system?
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Excretory: the respiratory system also
removes wastes (carbon dioxide) and
water from the body.
http://www.wisc-online.com/objects/index_tj.asp?objid=AP15104
Amazing Lung Facts
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At rest, a person breathes about 14 to 16 times per
minute. After exercise it could increase to over 60
times per minute.
New babies at rest breathe between 40 and 50 times
per minute. By age five it decreases to around 25
times per minute.
The total surface area of the alveoli (tiny air sacs in
the lungs) is the size of a tennis court.
The lungs are the only organ in the body that can
float on water.
The lungs produce a detergent-like substance which
reduces the surface tension of the fluid lining, allowing
air in.