HSS 3305 Lecture Notes - Lecture 16: Ulcerative Colitis, Gastric Mucosa, Helicobacter Pylori
Document Summary
Class 16: gastrointesinal diseases: muscular tube that extends from pharynx to stomach with sphincters at both upper and lower ends. Upper sphincter relaxes to allow passage of swallowed food. Lower (gastroesophageal or cardiac) sphincter relaxes to allow passage of food to the stomach. Failure of cardiac sphincter to funcion properly: more common. Tears in lining of esophagus from retching and vomiing. At gastroesophageal juncion from repeiive, intermitent, vigorous contracions that increase intra- abdominal pressure. Esophageal obstrucion from carcinoma, food impacion, or stricture. Two major disturbances of cardiac sphincter: cardiospasm: sphincter fails to open properly due to malfuncion of nerve plexus; esophagus becomes dilated proximal to constricted sphincter from food retenion. Botulinum: inhibit ns to contract => swallow: incompetent cardiac sphincter: sphincter remains open; gastric juices leak back into esophagus. Ulceraion and scarring of squamous mucosal lining. Barret"s esophagus: glandular metaplasia; change from squamous to columnar epithelium; risk for cancer.