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6 Cards in this Set
- Front
- Back
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Anatomy of Stomach
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4 main regions:
1. cardia 2. fundus 3. body 4. pylorus (include antrum) -rugae: ridges when stretched = smooth 2 sphincters: 1. LES 2. Pyloric 3 Layers to Muscularis Mucosa: 1. Outermost longitudinal layer 2. Middle ciruclar layer 3. innermost oblique layer |
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Stomach Mucosa
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-lining = muscosa; impermeable to acid
-property allows stomach to contain acid & pepsin w/o having its wall digested -several factors contribute to protection: imperm epith cell surface covering, mxn for selective transport of H+ & HCO3 & char. of gastric mucus = GASTRIC MUCOSAL BARRIER |
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Gastric Pits
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-mucosal surface of stomach simple columnar epithelium that is dotted w/ millions of deep channels = pits
-lined w/ column of sp. cells called gastric glands |
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Gastric Gland Cells
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1. Parietal Cells: secrete HCL & intrinsic factor (IF)
-prim found in fundus 2. Chief Cells: secrete pepsinogen & gastric lipase -prim found in body 3. Mucous Neck Cells: secrete alkaline mucus 4. Endocrine Cells: secrete gastrin; some enterochromaffin like cells secrete histamine -found in antrum |
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Gastric Glands
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-secrete ~2500 ml of gastric juice daily
-HCl secreted by parietal cells kills many ingested bacteria, aids protein digestion, provide nec. pH for pepsin to start protein digest & stim. flow of bile & pancreatic juice -concentrated enough to cause tissue damage (but mucosa protects) -mucus=flex gel that coats gastric mucosa -surface mem of gastric mucosal cells & the tight jxn bw cells are also part of mucosal barrier -substance that tend to disrupt barrier cause gastric irritation (gastritis), include ethanol, vinegar, bile, salts, & NSAIDS (aspirin & ibuprofen) |
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Fxns of the Stomach
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-acts as "warehouse" temp. stores ingested liquids & solids until they are released into small intestine
-stomach can hold ~5L empties slow bc duodenum can only hold ~200ml -mxl digestion: stomach vigor churns food into creamy soupy paste = chyme (goes to SI) -secretes gastric juice that involved w/ chemical digestion -secretes hormone gastrin & histidine (acts as endocrine gland) |
