80 IMMUNOLOGY 



the latter may traumatize the tissue and infection result. Opie, many 

 years ago, showed that acute pancreatitis (inflammation of the pan- 

 creas) may result from mechanical blocking, infection and the forc- 

 ing of bile up into the pancreas. Inflammation of the gall bladder 

 is called cholecystitis. This is usually due to extension of infection 

 from some focus in the body and may in some instances result in 

 multiple abscesses of the liver. A knowledge of the regional 

 lymphatics and of the anastomoses of tlie portal circulation is of 

 considerable value in visualizing the possible complications of 

 infections of tissue drained by them. 



Appendicitis. — Inflammation of the appendix is of rather fre- 

 quent occurrence. While theoretically the route of infection may 

 be hematogenous or lymphogenous, an examination of sections from 

 inflamed appendices suggests that the infection frequently starts 

 from injury to the mucosa. Fecaliths and small foreign bodies are 

 found quite frequently and there are numerous reports of finding 

 animal parasites within the lumen. Since the appendix is a blind 

 vestigial organ, stasis of fecal material within it must be quite 

 common. Thus one can see there is abundant opportunity for both 

 mechanical and chemical injury to the mucosa while the feces 

 in the region of the caecum is notoriously rich in bacteria. There 

 is also the added possibility that vasomotor disturbances might 

 cause vascular changes in the wall of the appendix and to some 

 extent lower the resistance of the tissue. 



The complication most feared by the physician is the rupture of 

 an infected appendix. This permits pus from the appendix as 

 well as fecal material with its rich bacterial flora to enter the 

 peritoneal cavity and cause peritonitis. INIeasures usually em- 

 ployed to avoid such a catastrophe are surgical interference or bed 

 rest with symptomatic treatm.ent designed to keep the intestine 

 at rest and to get the patient ready for operation if such is decided 

 upon. By the term ''get the patient ready for operation" is meant 

 to employ measures that will tend to restore his physiological 

 mechanisms to as near normal as possible. If he is dehydrated, 

 he will be given fluids; if anemic, he might be transfused, etc. 



Importance of Blood Supply at Lower Orifices. — At the 

 lower end of the intestinal tract and also in the genitourinary tract 

 there is a rich blood supply that is an important factor in defense 

 against infection since trauma is not uncommon, and infectious 



