2. RESPIRATORY SYSTEM AIR-can’t live without it!!

3. 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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5. 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 http://www.smm.org/heart/lungs/breathing. htm Boyle’s law-PV=nRT There is an inverse relationship between pressure and volume

6. ALVEOLUS (I)

7. 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

8. 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

9. Gas transport Oxygen transported on hemoglobin Hb+ O2  HbO2 CO2 transported in blood as bicarbonate ion (HCO3-) lower blood pH (free H+)

10. 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

11. Reflexes Cough Hiccup Sneeze Yawn Laugh/Cry –not reflex but under emotional control