Distension of the lungs : its effect on the respiration in man and in normal and vagotomized dogs / by Walter M. Boothby and Frank B. Berry.

  • Walter M. Boothby
Date:
[1915?]
Catalogue details

Licence: In copyright

Credit: Distension of the lungs : its effect on the respiration in man and in normal and vagotomized dogs / by Walter M. Boothby and Frank B. Berry. Source: Wellcome Collection.

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    ,'i * * erroneously interpreted as evidence of vagal influence. On the other hand, his experiments are very accurately described and profusely illustrated by kymographic records, and the data are still of great value and capable of reinterpretation. Haldane and Lorrain Smith4 later showed that, in rabbits, the pause in the respiration, produced during distension of the lungs, was not due to a lowering of the alveolar carbon'dioxide pressure. In consequence, this particular experiment has survived as the only example of a “ natural stimulus” which produces respiratory inhibition by stretching the vagi. Very recently Christiansen and Haldane5 have studied the ef¬ fect of distension of the lungs on the human respiration. They made use of a bag containing air and so weighted that the air was under a pressure of 6 to 8 cm. of water. The subject, breathing through a mouthpiece, could be connected, by means of a three-way tap, either to the air of the room or to the air in the bag. They invariably found that distension of the lungs caused the respirations to cease, usually for about half a minute. The pause was then broken by a deep expiration, followed by a further pause before the next expiration, and so on with increas¬ ingly shorter pauses. On turning the tap, so that the subject again breathed atmospheric air, the pauses disappeared, and the breathing returned to normal. By the use of air containing 7.3 per cent carbon dioxide and 8.2 per cent oxygen, the pause is pro¬ duced just as with pure air; the pauses succeeding the first, how¬ ever, diminished in length much more rapidly than when pure air was used. This pause was, therefore, not dependent on a lowering of the carbon dioxide tension of the arterial blood. In addition to the above Hering and Breuer “ inhibitory” effect, which is not dependent on chemical changes in the blood, Chris¬ tiansen and Haldane were able to obtain clear evidence of an independent phenomenon by the fact that under certain condi¬ tions an increase of carbon dioxide in the alveolar air will break 4 Haldane and Lorrain Smith: The physiological effects of air vitiated by respiration. Jour. Path, and Bact., 1892, i, 168-186. 5 Christiansen and Haldane: The influence of distension of the lungs on hu¬ man respiration. Jour. Physiol., 1914, xlviii, 4, 272-277.
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