An Extreme Mismatch of Ventilation and Perfusion Consider a

An Extreme Mismatch of Ventilation and Perfusion Consider a lung with two parts. In each part, the ventilation -perfusion ratio is constant. Suppose that the airflow and blood flow are as follows: (VA)1 = 5.0 liters/min, Q1 =0.0 liters/min, (VA)2 = 0.0 liters/min, Q2 = 5.0 liters/min. Calculate f, , and in terms of Pi, Pv, sigma, and kT. Explain your results in words. Optimal Gas Transport in a Two-Compartment Lung Consider a lung with two parts where in each part the ventilation-perfusion ratio is constant. Assume that P1 = 0, sigma kT = 1, Q1 =2.0 liters/min, Q2 = 3.0 liters/min, and (VA), = (VA)1 + (VA)2 = 5.0 liters/min. Find a formula for E as a function of (VA). Note that (VA)2 = (VA), - (VA) 1. Determine the value of (VA)1 that maximizes E by setting dE/d(VA)1 = 0. Interpret your result in terms of ventilation/perfusion ratios. Evaluate E max, the value of E when (VA)1 has the optimal value determined above. Plot E, /Pv, /Pv, as functions of (VA)1 over the interval 0

Solution

Amount of air getting to the alveoli and the amount of blood being sent to the lungs

V/Q=(4 I/min)/(5I/min)

V/Q=0.8