Some remarks on the mechanism of respiration / by F. Le Gros Clark.

  • Clark, Frederick Le Gros, 1811-1892.
Date:
[1872]
Catalogue details

Licence: Public Domain Mark

Credit: Some remarks on the mechanism of respiration / by F. Le Gros Clark. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    24. In ordinary expiration no muscular action is exerted ; but in extra- ordinary expiration the ribs are drawn down by the abdominal muscles, at the same time that the abdominal viscera are pressed upwards. The in- tercostals assist in this act when the lower ribs are thus fixed. The levator aui is an essential auxiliary in forced expiration. I do not attach much value to the agency of the triangularis sterni and serratus posticus inferior as muscles of expiration. I am disposed rather to regard them as agents in steadying the ribs for the diaphragm, and as antagonists, severally, to the pectoral and latissimus dorsi muscles, thereby affording them a more fixed attachment at their origin. 25. The generally received assertion that there is a marked difference in the respiration of the two sexes, i. e. man and woman, confirmed, apparently, by the observations of Hutchinson on young girls, has always struck me as very remarkable ; for, whatever hypothesis may be adduced to favour the relative advantage of such peculiarity, as regards woman, there certainly is no anatomical difference, either in the natural osseous conformation of the chest or in the muscular apparatus of respiration, to account for the predominance of the abdominal type of breathing in the male, and of the thoracic type in the female. It naturally occurs to any one, in contemplating this circumstance, to attribute something to the peculiar dress of civilized women—the fashion of compressing the lower part of the chest, which is universal. There can be no doubt that this compression, commenced as it is at a very early period amongst all classes, long before the development of the skeleton is completed, must exercise a permanent influence in altering the form of the chest, and must thus impart a factitious reality to that which is not natural. I believe that the early age at which this compression is begun, even amongst the lower orders, as I have ascertained by inquiry, has possibly misled so careful an observer as Hutchinson. I have repeated his experiments on young boys and girls, but with results at variance with those which he obtained. These results may be thus stated. 26. In ordinary respiration the upper costal respiratory movements are equal in male and female ; they are increased in both by girding the abdomen and lower ribs with a roller. The lower costal movements are also equal in the two sexes, and are not perceptibly affected by the action of the roller. The difference in the thoracic girth between ordinary expiration and inspiration is very slight, indeed scarcely perceptible. 27. In extraordinary respiration the costal movements, both upper and lower, are much greater in forced inspiration in the male than in the female. The lower costal movements are much interfered with, in both, by the compression of the abdomen and lower part of the chest, while the upper costal movements are exaggerated. I may add that, in the adult female, there is, as might be expected, a striking difference in the relative mobility of the chest and abdomen, when