The Respiratory System

at a Glance

Jeremy Ward, Jane Ward and Richard Leach

Multiple Choice: Chapter 15 Ventilation–perfusion mismatching

Question 15.1. In a person with ventilation-perfusion mismatching

a regions with ventilation-perfusion ratios of 0.3 are dead-space effect regions
b regions with high ventilation-perfusion ratios have equal and opposite effects on arterial Pco2 and Po2 as regions with low ventilation-perfusion ratios
c regions with low ventilation-perfusion ratios are the main cause of cyanosis in a patient with a severe asthma attack
d the effects on arterial Po2 and Pco2 are usually quite different from those of a pure right-to-left shunt.