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Published byPablo Songer Modified over 9 years ago
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Buccinator Sublingual gland Wharton’s duct Stensen’s duct Masseter muscle Parotid gland Mandible Submaxillary Gland Buccal Cavity: Primary Salivary Glands
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Filtration: In the Acinus is Primarily Passive Acinar cells Myoepithelial cell Ductal cells Acinus Myoepithelial cell Intercalated duct Striated duct Organization of the “Salivon”
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Digestive: -Amylase: Starch Digestion -pH optima 7.0; Active in Proximal Stomach -Ligual Lipase: Fat Digestion -pH optima ~4.0; does not require bile salts Lubrication/Protection: -Anti-Bacterial: I -, SCN -, Secretory IgA, Lysozyme and Lactoferrin -Anti-Corrosive: HCO 3 to buffer pH; F - Ca 2+. -Lubrication: Mucus- Mucopolysaccharides, H 2 O - Coat the Food to Aid in Swallowing-Taste Prevent Abrasion Functions of Saliva: Digestion, Protection-Lubrication
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Filtration: In the Acinus is Primarily Passive Organization of the “Salivon” Acinar cells Myoepithelial cell Ductal cells Acinus Myoepithelial cell Intercalated duct Striated duct Capillaries SP Acetylcholine SP: Substance P
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Stomach Anatomy
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Gastric Lumen Gastric Pits Columnar Epithelium Lamina Propria Gastric Gland Lymph Node Lymphatics Mucosa Sub- Mucosa Mucularis Serosa Gastric Pits and Glands
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Gastric Lumen Mucus Superficial epithelial cells Mucus neck cells Parietal cells Peptic cells (Oxyntic) GASTRIC GLANDS Gastric Pits
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The Epithelial Protective Barrier Tight Junctions between Adjacent Cells Mucus and Bicarbonate Secretion Rapid Turnover – Cell Migration and Proliferation : All Appear to be Driven by Prostaglandins
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Oxyntic Gland Secretions Peptic GastroferrinIron Binding Protein P Pepsin-ogen Protease D Mucus Neck Mucopolysaccharides; HCO 3 P Oxyntic Intrinsic Factor B12 BindingD Protein HCl Digestion/ P/D “denaturation” Cell Type Component Function: (P/D) P- Protective; D- Digestive
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Protein Digestion : - Activates Pepsin - Denatures and Solubilizes Tissue Protective: Kills Bacteria Roles of HCl in the Stomach
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ATP K+K+ K+K+ K+K+ H+H+ H+H+ Na + Cl - HCO 3 - H 2 CO 3 CO 2 HCO 3 - Na + Lumen of gland ATP Canaliculus Metabolism Cl - CA CA – Carbonic Anhydrase Baso- Lateral The Oxyntic Cell
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CO 2 + H 2 O H 2 CO 3 HCO 3 - + H + Role of Carbonic Anhydrase CA
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Key Players: HCl Secretion H + / K + ATPase : Lumenal Omeprazole Carbonic Cytosolic Acetozolamide Anhydrase Na/K ATPase BasolateralOuabain K + / Cl - cotransport : Lumenal Cl - / HCO 3 antiport: Basolateral Location Inhibitor
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Acetylcholine Gastrin Histamine Ca 2+ La 2+ H+H+ A A CM A ATP cAMP Adenylate Cyclase Blocks Does not block Ca 2+ IP 3 A - ATROPINE Ln 2+ - Lanthanum CM - Cimetidine H + Secretion
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Phases of Secretion Cephalic Smell, Taste Central reflexes Gastric Chyme Enters Stomach Distension, Local Effects Amino Acids IntestinalChyme Enters Local Feedback the Intestine Inter-Digestive Histamine Basal Release PhaseStimuli Pathway
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Primary Mechanisms for Inhibiting HCl Secretion Antrum Acidification pH < 3 Somatostatin Inhibition ( Gastric ) Maximal pH < 1of Gastrin Secretion Duodenum Distension Enteric (Local) Reflexes ( Intestinal )pH < 6 Fat and Peptides Entero-gastrone? Location (Phase) StimuliPathway
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Ach GRP Vagus nerves Gastrin Cell Somato- statin Cell Digested Protein H+H+ + Regulation of G-Cell Secretion Myenteric Plexus
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Antrum Body ECL
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