Diseases of the anal canal

The anal canal, lined by squamous mucosa, is prone to several groups of diseases, many of which are extensions of diseases in the rectum.

Anal fissures(splitting of the mucosa with chronic inflammation) and fistulae (a sinus extending from the anus or the rectum) are commonly seen in association with Crohn's disease, but may also occur spontaneously.

Infectionsof the anal canal may be the result of sexually transmitted diseases, particularly chancres of syphilis, gonorrhea and amebic infections in homosexuals. Infection with human papillomavirus may cause condylomas in the perianal skin.

Tumorsof the anal canal are most commonly squamous cell carcinomas. Less commonly, adenocarcinomas, and small-cell carcinomas resembling oat-cell carcinomas occur.

Hemorrhoids,which are varicose dilatations of rectal veins, are very common.

Stages of individual work in class Study and describe macrospecimens

Chronic atrophic gastritis. Characterize the condition of the stomach mucosa (rugae, thickness). Are the specified changes of the mucosa combined with disturbances of secretion? Specify possible histological changes in the mucosa.

Chronic ulcer of the stomach. Specify localization, sizes and form of ulcerative defect, characterize the depth of the ulcer, its bed and edges. Describe what edge is inverted to the esophagus, and what edge to pylorus. Name possible ulcerous-destructive complications of chronic ulcer of the stomach.

Chronic ulcer of the stomach penetrating the pancreas. Define localization, sizes and depth of ulcerative defect, the appearance of the bed of the ulcer and underlaying organ. Explain what penetration is and why there is no defect in the stomach?

Chronic ulcer of the stomach with arrosion of the vessel. Give the macroscopic description of ulcerative defect, specify its localization, form, depth. Describe the edges of the ulcer, its bed and condition of the vessel. Explain the mechanism of the bleeding. What are clinical symptoms of gastric bleeding?

Acute phlegmonous appendicitis. Describe the changes of the appendix: its diameter, condition of serous coat and

vessels, contents of the lumen and thickness of the wall. Name possible complications of the described form of appendicitis. Empyema of the appendix. Appearance of the process, the sizes of the lumen (cavity and thickness of the wall). What exudate is present in the lumen? To what form of appendicitis does this case belong according to the course of the disease?