HLTH1030 Lecture 16: HLTH1030-Lecture 16
7 Nov 2018
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Document Summary
Bolus: what you swallow, chewed food mixed with saliva. Chyme: what goes into the small intestine (duodenum) from stomach, partially digested food and digestive juices (acids, enzymes) Empty stomach: mucosa forms many folds = rugae. Chemical: pepsin partially digests proteins into shorter peptide chains. Gastric lipase and lingual lipase begin fat digestion. The small intestine is the main organ of absorption but some things are absorbed by the stomach: water, alcohol, some medication (aspirin, anti-inflammatories) Duodenum can prevent overfilling by controlling how much chyme enters. Duodenal receptors respond to stretch and chemical signals. Enterogastric reflex and enterogastrones inhibit gastric secretion and duodenal filling. Stomach empties in ~4 hours, but increase in fatty chyme entering duodenum can increase time to 6 hours or more. Sphincter = work to control the passage: lower esophageal (cardiac) sphincter, pyloric sphincter. If erosions perforate wall, can lead to peritonitis and hemorrhage. Most ulcers caused by bacterium helicobacter pylori.
