1. 1. Pulmonary PhysiologyCHAPTER 1Structure and Function
2. 2. Primary functions of the lung Gas exchange Bring in O2Remove CO2Maintain acid base statusFilter bloodBlood reservoirMetabolizes some compounds
3. 3. Blood-Gas Interface Ideal suited for gas exchange Large surface area Thin surface the size of a tennis court-100 square meters 0.3 micrometers (1/1,000,000)Diffusion (or movement of gas) is proportional to surface area and inversely proportional to thickness
4. 4. Air Room air is 21% oxygen The partial pressure of oxygen in inspired gas is calculated by multiplying the percent oxygen by atmospheric pressure (after subtracting water vapor) This is a very important equation. You will see it again. Po2=FiO2(760-47)
5. 5. Example 0.5 x (760-47) = 356 mm Hg
6. 6. Breathing Not all the air we breath in is used for gas exchange The airways used to get air to the alveoli are the conducting airways (figure 1-4 in text). This contributes to dead space Any area of ventilated lung that is not perfused it dead space
7. 7. Blood Flow Pulmonary arterial blood pressure is very low Due to low resistance of pulmonary circulation Normal pressure about 15 mmHgSystemic blood pressure is about 80 mm Hg
8. 8. Structure and Function Normal CT
9. 9. Structure and Function Interstitial lung disease
10. 10. Structure and Function Food for thought How do other lung diseases show how structure affects function?How is this demonstrated radiographically?How is this demonstrated on blood gases?