A man has intrapleural pressure of (-5 cm H20) before inspiration and (-10cm H20) at the end of inspiration and he inspires 1200 ml from a spirometer. What shall be the the compliance of lungs?
Compliance is change in volume per unit change in pressure. C= DV/DP DV= 1200 mL DP= -10-(-5) = - 5cm of H2O The minus sign indicates that the pressure has fallen by 6 cms of H20 at the end of inspiration Therefore the compliance is, C= 1200/5= 240 mL/cm of H2O
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Respiratory System Pa 1