RESPIRATORY SYSTEMRESPIRATORY SYSTEMAIR-can’t live without it!!

1.NOSE-filter and warm air3. 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 lungs11. Bronchioles-smaller paths

within lungs12 and 13.Alveoli-functional

parts of lungs (300 million)

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BOYLE’S LAWBOYLE’S LAW

HOW does air get inPushed in by lower air pressure inside the

lungs than out (see website)http://www.smm.org/heart/lungs/breathing

.htm

Boyle’s law-PV=nRTThere is an inverse relationship between

pressure and volume

ALVEOLUS (I)ALVEOLUS (I)

Site of gas exchange with Site of gas exchange with bloodbloodDaltons law of partial pressuresPressure 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

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 transportGas transport

Oxygen transported on hemoglobin

Hb+ O2 HbO2 CO2 transported in

blood as bicarbonate ion (HCO3-) lower blood pH (free H+)

Respiratory controlRespiratory 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

ReflexesReflexes

CoughHiccupSneezeYawnLaugh/Cry –not reflex but under emotional

control