[Relationship between the control of the duration of inspiration and the resting ventilation pattern in conscious...

The relationship between tidal volume (V1) and inspiratory duration (T1) was studied in 5 subjects by a rebreathing procedure in pure O2. The range of this relationship marked by a decrease of T1 with increasing V1, related by Clark and Von Euler to the inhibitory vagal feed-back loop Breuer Hering or B.H. reflex, was only found in 3 subjects possessing the B.H. reflex. In the others, whose pattern of breathing was very slow, nor this range nor the B.H. reflex were found. These findings confirm previous owner data (2). Indeed in our subjects having a slow pattern of breathing, the control of T1 seems to be unrelated to vagal afferences coming from lung stretch receptors.