title: The breathing pattern after breath-holding: the influence of chest position and the drive to breathe.
abstract: The pattern of breathing following the breaking-point of sixty breath-holds has been studied in five healthy adults and compared with the pattern during recovery from CO2-rebreathing. The volume and direction of the first respiratory movement, and the VT, V relation for the first four complete breaths was measured. Only when breath-holds were terminated with an inspiration was the accumulated drive to breathe reflected in an increased volume of the first respiratory movement: terminating expirations simply returned the chest to the resting respiratory level. The volume of the first inspiration was not influenced by the intervention of a terminating expiration, suggesting that expiratory movements do not dissipate the non-chemical component of the drive to breathe. In three of the five subjects the tidal volumes for given levels of ventilation were greater following breath-holding than following rebreathing. This altered pattern of breathing has been interpreted in terms of an insiratory-augmenting reflex.
mesh_terms: D000328:Adult; D001049:Apnea; D002245:Carbon Dioxide; D005260:Female; D006801:Humans; D008168:Lung / Q000502:physiology*; D008297:Male; D011187:Posture; D012115:Residual Volume; D012119:Respiration; D013990:Tidal Volume; D014109:Total Lung Capacity
chemical_list: D002245:Carbon Dioxide