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Digestive System 3; Liver 1

Digestive System III; Liver I: In this lecture, Professor Diamond continues her review of the digestive system by describing the small intestine. She begins by describing the start and end points of the small intestine, the pyloric sphincter and the ileocecal valve, and demonstrating the 20 foot length. She discusses the sections of the small intestine including duodenum, jejunum, and ileum and how villi increase surface area. She discusses several unique characteristics of the small intestine, including the presence of Brunner’s glands in the duodenum, which neutralize low pH chyme from the stomach, and Peyer’s patches in the ileum, which serve as a local defense mechanism. Professor Diamond then moves on to describe the sections of the large intestine: ascending colon, transverse colon, descending colon, and sigmoid colon. She discusses the major functions of the large intestine, such as absorbing water. She highlights the longitudinal muscle structure of the large intestine and the unique distribution of adipose tissue. She then describes the rectum and its structure, and notes how swollen veins in the rectum result in hemorrhoids.