Question

1. How do the global and local reflexes address the optimization of the ventilation : perfusion ratio (keeping it close to 1)? Map your answers to (a) and (b) onto this concept.

Answer 1

There are regions in the lungs where ventilation an blood flow are not properly matched.Due to this physiological mismatching,a small fraction of cardiac otput is not normally fully oxygenated.The matching of airflow to blood flow is studied by examining the ventilation perfusion ratio.

Ventilation perfusion ratio is the ratio of alveolar ventilation to blood flow in the lungs.In a normal individual at rest,the alveolar ventilation is 4L/min and pulmonary blood flow is 5L/min.Thus normal ventilation perfusion ratio is 0.8.