Transcript RESPIRATORY SYSTEM

RESPIRATORY SYSTEM
AIR-can’t live without it!!
1.NOSE-filter and warm air
3. Epiglottis-covers opening to
lungs when eating; also
used when coughing,
sneezing
4. Trachea-filter and passage
to lungs
 Larnyx (not pictured)”voice box” air forced out
through vocal cords to
produce sound. Lips and
tongue make words
5. Bronchi-branches to lungs
11. Bronchioles-smaller paths
within lungs
12 and 13.Alveoli-functional
parts of lungs (300 million)
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BOYLE’S LAW
HOW does air get in
 Pushed in by lower air pressure inside the
lungs than out (see website)
 http://www.smm.org/heart/lungs/breathing.
htm
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Boyle’s law-PV=nRT
 There is an inverse relationship between
pressure and volume
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ALVEOLUS (I)
Site of gas exchange with
blood
Daltons law of partial pressures
 Pressure a gas exerts in a mixed gas is
equal to the percent of the total pressure of
the gas
 Example- O2 is 20% of air there fore is the
total pressure of air is 760 mmHg O2’s
pressure is about 156 mm Hg
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Refer to figure 23-19 and
table 23-1 (given to you)
pO2 of alveolus is 100
mm Hg
pO2 of blood entering
lungs is 40mm Hg
Therefore O2 moves
from high pressure to
low pressure or from
lungs into blood
(diffusion)
See figure 23-19 for
movement of gases
throughout body
Gas transport
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Oxygen transported
on hemoglobin
Hb+ O2 HbO2
CO2 transported in
blood as bicarbonate
ion (HCO3-) lower
blood pH (free H+)
Respiratory control
Control centers in pons and medulla
(brainstem) send messages down phrenic
nerve
 Medulla sensitive to CO2 concentrations
(decrease in blood pH) –increases
breathing rate in response
 There are also O2 sensors in blood vessels
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Reflexes
Cough
 Hiccup
 Sneeze
 Yawn
 Laugh/Cry –not reflex but under emotional
control
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