Respiratory exercises in the treatment of disease : notably of the heart, lungs, nervous and digestive systems / by Harry Campbell.

  • Campbell, Harry, 1860-1938.
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Respiratory exercises in the treatment of disease : notably of the heart, lungs, nervous and digestive systems / by Harry Campbell. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    the capacity of the intra-pulmonary portion of the pulmonary circuit; (2) by modifying the pressure upon the heart and such of the intra-thoracic bloodvessels as are outside the lungs, namely, the aorta and its branches, the pulmonary artery and its extra-pulmonary branches, the innominate veins and their branches, the venae cavfe, the azygos veins, and the pulmonary veins ; (3) by modifying the intra- abdominal pressure. 1. With every mspiration the vessels of the lungs expand, contracting again during expiration,* the degree of vascular expansion and contraction being, under ordinary circumstances, in direct proportion to the degree of inspira- tion and expiration. That the intra-pulmonary vessels should open up when the lungs expand and shrmk again when they contract, seems natural enough, but the exact reasons for these alterations in calibre are not so easy to determine. During inspiration the pressure in the alveoli falls, and that in the pleurae, already negative, falls still further, so that the effect of inspiration on the lungs is much the same as that which would be produced by placing them in the reservoir of an air-pump and then exhausting the air, having previously ligatured the pulmonary artery and vems. We know that under these circumstances the intra-pulmonary vessels would dilate, and, indeed, the inspiratory increase in the vascular capacity of the lungs has been attributed to a species of dry cupping.f It must not, however, be supposed that this increase is due solely to diminution of the atmo- * It has been experiiuentally sho\vii that the pulmonary vessels are more capacious after inspiration than after expiration (see McKendrick's ' Physiology,' vol. ii., p. 290). ' If,' writes P. M. Chapman, ' at the termination of expiration the quantity of blood in the lungs is from i'.> to iV of the total (Quantity of blood in the bod}-, at the termination of inspiration it will be from ,V to i'...'—Lancet, 1894, vol. i., p. 587. t See Michael Foster's ' Textbook of Physiology,' sixth edition. Part II., p. 650. 6—2