THE DIGESTIVE SYSTEM. 569 



similar conditions in the pleura and pericardium. Chylous ascites may 

 result from a rupture of the thoracic duct or from a transudation from 

 the chyle vessels. ' 



INFLAMMATION. (Peritonitis.) 



Acute Peritonitis. Acute inflammation of the peritoneum may occur 

 as a primary process, but is much more often secondary. In the latter 

 case it may be associated with wounds and contusions of the wall of the 

 abdomen; wounds, ulcers, new growths, incarcerations, intussuscep- 

 tions, ruptures, perforations, and inflammations of the stomach and in- 

 testines; inflammation of the vermiform appendix ; injuries, ruptures, 

 and inflammations of the uterus, ovaries, and Fallopian tubes; rupture 

 and inflammation of the bladder ; inflammation of and about the kidneys ; 

 abscesses and hydatid cysts of the liver ; inflammation of the gall-bladder 

 and large bile ducts ; thrombosis of the portal vein ; inflammations of the 

 spleen, pancreas, lymphatic glands, retroperitoueal connective tissue, 

 vertebrae, ribs, and pelvic bones ; pyaemia and other infectious diseases. 

 The inflammation is at first either local or general. A local peritonitis 

 may remain circumscribed, or it may spread and become general. 



We may distinguish two anatomical forms of acute peritonitis. 



1. CELLULAR PERITONITIS. This form of peritonitis may be in- 

 duced by any irritant which does not act too energetically. It can be 

 excited in dogs by intraperitoneal injections of very small quantities 

 of a solution of chloride of zinc. In the human subject we find it with 

 perityphlitis, with circumscribed abscesses in the peritoneal cavity, in 

 puerperal fever, and other infectious diseases with early death. 



At the autopsy the entire peritoneum may be congested ; but there 

 are no exudates and no other lesions visible to the naked eye. Minute 

 examination, however, shows a very marked change in the mesothelial 

 (endothelial) cells. These are increased in size and number, and the 

 new cells coat the surface of the peritoneum and project outward in lit- 

 tle masses (Fig. 346). This form of inflammation, in many cases at least, 

 if life be prolonged, passes into the exudative phase, next to be considered. 



2. EXUDATIVE PERITONITIS. This which is the common form of 

 acute peritonitis presents lesions similar to those which have been already 

 described in pleuritis and pericarditis. Thus there is a form in which 

 fibrin is the chief exudate with but little serum ; or the exudate is sero- 

 fibriuous, or purulent, or hsemorrhagic. When fibrin is present, the in- 

 testinal coils may be more or less firmly adherent to the abdominal walls 

 or to each other. If putrefactive bacteria be present, as in peritonitis 

 from perforation of the intestine, the exudate may be foul. 



T n local inflammation of the peritoneum the position may be indicated 

 by the name, thus perihepatitis, perisplenitis, perityphlitis, pelvic, sub- 

 phrenic, etc. 



1 For a study of milky fluids in serous cavities consult Skate, Jour. Path and Bact., 

 vol. vi., p. 339/1900, bibliography. 



