A quantitative description of the pattern of breathing during steady‐state CO₂ inhalation in man, with special emphasis on expiration

Abstract

SUMABLY1. Quantitative data on the pattern of breathing in normal men and women (Gardner, 1977)

Dependence of phrenic motoneurone output on the oscillatory component of arterial blood gas composition.

“…Experiments in man and animals have demonstrated that chemical stimuli can influence inspiration and expiration independently (Drysdale & Ward, 1976;Eldridge, 1976;Gardner, 1977;Cunningham & Gardner, 1977;Ward & Cunningham, 1977). The effects of a change in q in the present experiments on phrenic motoneurone output can satisfactorily be accounted for by relating Ti and Phr to the chemical events at the carotid body during inspiration and also by relating Re to the events occurring during expiration.…”

“…The independent effect of Phr on Ti and Te suggest that separate functional mechanisms are involved in the control of the two phases of the respiratory cycle, at least in the vagotomized dog. The findings have some resemblance to those obtained in conscious man when ventilation was stimulated either by alternate breath oscillations of alveolar PCo2 (Drysdale & Ward, 1976), or by steady-state CO2 inhalation (Gardner, 1977;Cunningham & Gardner, 1977). It may be relevant to note that in conscious man in eupnoea, there is no evidence of any vagal control of breathing (Guz, Noble, Widdicombe, Trenchard, Mushin & Makey, 1966).…”

The relation between tidal volume and inspiratory and expiratory times during steady‐state carbon dioxide inhalation in man

“…The most consistent functions for locating the breakpoint were PA, co, VS. VT (high oxygen points only) and VT/TI versus VT, both of which were usually bilinear (see Gardner, 1975;Cunningham & Gardner, 1977). The discontinuity between the two lines in both plots corresponded well with the breakpoint as estimated by eye from the volume-time plots.…”

“…In general, for man, the inspiratory part of the pattern of ranges 1 and 2 shown on the right of Fig. 1 Hey et al (1966) is presented in a companion paper (Cunningham & Gardner, 1977). Some of this work has appeared in abstract form (Cunningham & Gardner, 1972;Gardner, 1975 (VG-Micromass Ltd, Winsford, Cheshire, England).…”

The effects of beta‐adrenoceptor blockade on breathing during progressive exercise in normal man.

“…However, other authors have shown in animals that, whereas a major component of the ventilatory response is mediated via the arterial chemoreceptors, a significant component is the result of direct effects on the central nervous system (Eldridge & Gill-Kumar, 1980;Winn et al, 1979). Folgering (1980) (Hey et al, 1966;Cunningham & Gardner, 1977;Gardner, 1977 (Bailey, 1959).…”