Openings frequently occur in consequence of disease or violence. Ulcers often make a perforation, and it is common enough to see an abscess of the liver make its way into the lung through the diaphragm. The writer lately saw an abscess, which formed in the gastrosplenic omentuni, take the same course. Wounds often penetrate the diaphragm, and it is remarkable that however small they may be, a ventral phrenic hernia is sure to follow.
The diaphragm has been suddenly ruptured during violent muscular efforts, vomiting, falls, &c. and instant death has usually followed. Various examples of such ruptures are recorded in the Dictionnaire des Sciences Med. art. Diaphragme. The countenance in all such cases assumes the peculiar expression or grin called risus Sardonicus.
The diaphragm is subject to attacks of in flammation, which, in almost every case, is communicated to it by the adhering pleura or peritoneum. It is indeed usually confined to one or other of these serous membranes, chiefly the pleura, and does not affect the muscular fibre. It is, notwithstanding, termed diaphrag mitis. Hippocrates called it phrenitis, and Boerhaave changed the name to paraphrenitis, to distinguish it from a well-known cerebral affection.
angrene, collections (2f pus, tumours, &c. are occasionally met with, and are of very difficult diagnosis.
Cartilaginous and osseous deposits have been found on both sides of the diaphragm in the subserous cellular tissue.
The diaphragm is often considerably dis placed upwards or downwards. In ascites, and in consequence of diseases of the liver and of abdominal tumours, it may be pushed up to the second rib on one side ; in thoracic affec tions again it has been so pushed down as to become convex, in part of its extent, towards the abdomen. Senae mentions a case of great enlargement of the heart which caused the cen tral tendon to be buried in the abdomen, it being formed into a kind of pouch.* Dr. W. Stokes found the left ala convex towards the abdomen in emphysema of the lungs,t and it is known to yield extensively to the pressure of fluid in cases of cmpyema, more especially if the pleura covering it has been much engaged, as the same accurate observer has noticed and explained.