PHGY 210 Lecture Notes - Lecture 14: Blood Gas Tension, Chronic Obstructive Pulmonary Disease, Asthma

• School: McGill University
• Department: Physiology
• Course: PHGY 210
• Professor: Ann Wechsler

Document Summary

Viii ventilation during exercise: tidal volume and breathing frequency during exercise. Comparisons of the components determining pulmonary minute ventilation (ve) during progressive exercise up to maximum: When exercise starts, both tidal volume (vt) and breathing frequency (f) increase proportionally (figure 46 a & b). Consequently, peak expiratory flow rate increases more than peak inspiratory flow rate. see pictures in slides: minute ventilation and metabolic rate during exercise. In both untrained and trained subjects, minute ventilation (ve)(dot) increases linearly with metabolic rate (vo2)(dot) up to about 50% to 65% of vo2(dot) max (figure 47). Thereafter, ve(dot) increases at a rate disproportionately greater than the change in vo2(dot). Note that an effect of endurance training is to delay the ventilatory inflection point (tvent). see picture in slides. Is ventilation a limiting factor in aerobic performance at sea level? (ve/q) Resting values of ve can increase 35 folds during exercise (from 5l/min to 190.