Contributions to the anatomy of the Indian elephant. Pt. I. The thoracic viscera / by Morrison Watson.

  • Watson, Morrison.
Date:
[1872]
Catalogue details

Licence: Public Domain Mark

Credit: Contributions to the anatomy of the Indian elephant. Pt. I. The thoracic viscera / by Morrison Watson. 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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    siderably injured before I commenced the dissection, the descrip- tion is not so perfect as might otherwise have been the case. The greater portion of the diaphragm was occupied by the central tendon, from the margin of which the muscular fibres passed off to their attachment to the circumference of the tho- rax. These two parts differed materially from one another, for whilst the central tendon was very thick and strong, the mus- cular portion of the septum, on the other hand, was thin, and the bundles easily separated. An arrangement, however, to strengthen this deficiency was,present, consisting of two plates of yellow elastic tissue, one covering each of the surfaces of the muscular portion of the diaphragm. Both of these plates of elastic tissue passed imperceptibly into the substance of the central tendon and there lost themselves. The anterior plate differed from the posterior in this,—that, whilst the posterior plate covered every part of the muscular portion of the dia- phragm, the anterior was confined to that part of it which came into relation with the base of the pericardium, and shaded off beyond this region to the left side into a muscular fascia of considerable strength, and composed of fibrous tissue, whilst to the right, owing to the diaphragm having been cut, I could not follow it to its termination. This much however is to be said, that a considerable admixture of fibrous with i the yellow elastic tissue having already taken place, seemed to imply that on the right, as on the left side, this elastic plate gradually shaded off into a fibrous' tissue. If this supposition be correct, then we must regard the anterior elastic plate as being connected physiologically with the pericardium, and not with the diaphragm. The probability of this view will be in- creased when the attachment of the pericardium to the dia- phragm is considered. John Hunter1 statc-s that “The pericardium adheres to the diaphragm nearly as in the human, but not so closely and fiimly, but a more correct description would be that it forms an intermediate stage between the completely free pericardium as described by Prof. Turner in the walrus*, and the closely ad- cient human pericardium. Its posterior surface is smooth, 1 Essays and Observations by Owen, ii. 172. Journal of Anatomy and Physiology, November, 1870.