Dr and the Tree

Upload Explain why the absolute magnitude of the inspiratory and expiratory pressures is so much greater than the passive pressure?

inspiratory and expiratory pressures are greater than passive pressure because air flow in inspiratory and expiratory are increased greater (more positive) expiratory pressures were developed at higher VL, while greater (more negative) inspiratory pressures were developed at lower VL |

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2. Explain why the pressure is negative for maximum inspiratory pressures and positive for maximum expiratory pressures. At what stage of the inspiratory cycle pressure most negative, and at what stage of the expiratory cycle is pressure most positive?

Inspiratory cycle pressure is most negative after normal tidal inhalation, expiratory cycle is most positive after maximum inhalation |

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Figure 1: Passive pressures.

3. Figure 1 above shows representative values for the passive pressures measured in the respiratory system. Briefly state how each of these 3 pressure curves is obtained.

The static V-P curves of the respiratory system, chest wall, and lung were obtained by plotting the different inflating volumes (expressed relative to Vr) |

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4. Three lines are drawn on the diagram. State what lines A, B and C represent. What is the physiological significance of each of these three points?

A is total lung capacity, B is vital capacity, C is tidal volume |

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5. In which part of the passive pressure curve is the compliance of the lungs and chest wall together, highest? (Remember, compliance - dV/dP - reflects the ease with which a change in pressure can produce a change in volume). What is the physiological significance of this?

Passive pressure curve the lung and chest wall together are highest at the total lung capacity at 60/10. The significance of this is that The change in lung volume per unit change in airway pressure (V/P) is the compliance (stretchability) of the lungs and chest wall. Compliance is a static...