Licence: In copyright
Credit: Remarks on diaphragmatic herniae / by Arthur Keith. 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.
1/6
![DIAPHRAGMATIC HERNIAE. BY ARTHUR KEITH, M.D.Aberd., F.R.C.S.Eng., CONSERVATOR OF THE MUSEUM AND HUNTERIAN PROFESSOR, ROYAL COLLEGE OF SURGEONS, ENGLAND. If one may judge from current medical literature, tbe passage of viscera from the abdomen to the thorax through a defect in the diaphragm is not an uncommon form of hernia. Dr. J. W. Ballantyne found records of 100 cases published between 1888 and 1900; an excellent article on 63 cases was published by Mr. Lawford Knaggs in 1903; in the same year M. Paillard was able to give references to 481 described cases. In spite of the extensive literature, the cause and significance of the defects of tbe diaphragm which render such hernia possible are ill understood—a natural result of our present imperfect knowledge of the origin and history of that muscle. The history of the diaphragm is linked up with that Jaeger and still unsettled problem— the origin of tbe mammals, and especially of their peculiar respiratory mechaniem. At the present time the diaphragm is regarded by most anatomists as a septum which has grown across the coelomic cavity, dividing it into pleural and peritoneal compartments. When, however, one begins to account for the various characters of the diaphragm, its origin in the neck of the embryo, its nerve supply from the fourth and fifth cervical neives, and especially for the manner in which this effective part of the mammalian mechanism gradually assumed its present functional character, it becomes evident that its origin as a transcoelomic partition provides a very imperfect working hypothesis. The explanation I offered in the Journal cf Anatomy and Physiology some five years ago still appears to mo the most satisfactory. The pleural cavities are, to my way of thinking, similar in many respects to the tunicae vaginales; both are extrusions or extensions of the primary coelomic cavities, but whereas the testicles have extruded in front of them an extension of all three primary layers from the hind end of the primary abdominal cavity, the lungs perforate only the inner of the three layers of the fore end of that cavity, and instead of being extruded in the [531/10]](https://iiif.wellcomecollection.org/image/b22437150_0003.jp2/full/800%2C/0/default.jpg)
