pulmonary physiology online week 1: structure and function
TRANSCRIPT
- 1. Pulmonary PhysiologyCHAPTER 1Structure and Function
- 2. Primary functions of the lung Gas exchange Bring in O2Remove CO2Maintain acid base statusFilter bloodBlood reservoirMetabolizes some compounds
- 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. 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. Example 0.5 x (760-47) = 356 mm Hg
- 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. 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. Structure and Function Normal CT
- 9. Structure and Function Interstitial lung disease
- 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?