Term
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Definition
motility: longitudinal and circular muscles; top 1/3 is striated; other 2/3 is smooth
Secretion
Digestion
Absorption: 3000 to 6000 microvilli/epithelial cell |
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Term
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Definition
Anatomy: Fundus, Orad (top 1/3), body, caudad (bottom 2/3), antrum
Cell type: Parietal (body, HCl, intrinsic factor); Chief (body, pepsinogen); G cells (antrum, gastrin); mucous (antrum, mucous, pepsinogen) |
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Term
| Stomach cell (lumen to muscle) |
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Definition
| epithelial cells, mucous, parietal, and chief |
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Term
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Definition
•gastric emptying takes 2-3 hrs
•pancreatic and biliary secretions
•digestion of protein, carbohydrate, and fat:
o proteins: aa’s, di and tripeptides
o carbs: monosaccharides
o lipids: micelle formation, reesterfication and secretion into lymph as chylomicrons |
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Term
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Definition
| absorption of Na+, amino acid/sugar at lumen and Na+, amino acid/sugar, HCO3- at blood side; H+ release at lumen; K+ absorption at blood |
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Term
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Definition
At lumen: Na-amino acid/sugar symport; Na-H+(out) exchanger; HCO3 (out)-Cl- exchanger; B12 and bile salts
At blood: Na-K-ATPase; sugar/amino acid transporter; Cl- transporter; B12 and bile salt transporter |
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Term
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Definition
Secretion: alkaline mucus; Na absorption-dependent on aldosterone; K secretion-diarrhea can lead to hypokalemia
Bacteria: Vit K production, increased colonic acidity, motility and mucosal integrity
Absorbs water and salts |
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Term
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Definition
Parasympathetic: excited by conditioning, food, nausea, smell; inhibited by fear, dehydration, sleep; CN VII and CN IX; ACh/Metabotropic receptor; IP3,Ca
Sympathetic: T1-T3, NE/beta receptor; cAMP |
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Term
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Definition
Pancreatic enzymes (islet or acinar cells): insulin, glucagon, trysinogen, chymotrysinogen, proelastase, procarboxypeptidase A and B
Lumen Ductal cells: secrete bicarbonate; absorb Cl-
Blood ductal cells: Na-K ATPase; Na-H exchanger
Between cells: Na+ |
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Term
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Definition
• Digestive function
o bile production and secretion
• Non-digestive function
o processing of nutrients – glucose, lipids
o synthesis of plasma proteins
clotting factors
transport proteins
o Storage: glycogen, fats, iron, copper
o vitamin D activation – important for Ca2+ uptake
o removal of bacteria
o removal of old RBCs
o excretion of bilirubin
o detoxification of body wastes
o drug metabolism (xenobiotics) |
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Term
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Definition
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Term
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Definition
• enteric – can self-regulate (gap junctions play a big role in coordinating contraction) with feedback coming from mechano- and chemoreceptors; in GI wall
o submucosal plexus – closer to lumen
o myenteric plexus – closer to blood |
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Term
| Parasympathetic extrinsic |
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Definition
• parasympathetic
o long preganglionic and short postganglionic fibers
o ganglia are in plexuses named above
o ACh – causes contraction of muscles of GI wall and relaxation of sphincters; increased salivary secretion, gastric secretion, and pancreatic secretion |
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Term
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Definition
o short preganglionic and long postganglionic fibers
o Ganglia are outside effector organ
o NE – relaxes muscles and contracts sphincters; increased salivary; |
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Term
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Definition
• tonic –constant level of tone; found at sphincters (circular muscle)
• phasic – contraction/relaxation cyles; longitudinal muscle
• peristaltic – coordinated muscle contraction to push in one direction
• segmental – to divide in two directions for mixing purposes |
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Term
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Definition
| stem cells are located in the crypt (valley between individual villi) |
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Term
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Definition
| pepsin (stomach), trypsin, chymotrypsin, elastase, carboxypeptidase A and B |
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Term
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Definition
Starch: alpha amylase
Dextrins: alpha dextrinase
Maltose: maltase
Maltotriose: sucrase
Trehalose: trehalase
Lactose: lactase (glucose,galactose)
Sucrose: sucrase (glucose, fructose) |
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Term
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Definition
Triglyceride--lipases--MG and FFA
Cholesterol ester--cholesterol ester hydrolase--cholesterol and FFA
Phospholipid--phospholipase A2--lysolecithin and FFA |
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Term
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Definition
| Liver--bile duct--gall bladder--bile duct--duodenum--bile salt absorption in ileum--portal circulation--Liver |
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Term
| H+ secretion and inhibition in parietal cell |
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Definition
Vagus--ACh/M3 receptor--G4--IP3,Ca--H-K ATPase--H+
G cells--gastrin/CCKB--G4--IP3,Ca--H-K ATPase--H+
ECL cells--Histamine/H2--G5--cAMP--H-K ATPase
Somatostatin and Prostaglandins block cAMP |
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Term
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Definition
| gastrin releasing peptide |
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Term
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Definition
Where: I cells of duodenum and jejunem
Why: amino acids
What: increase pancreatic secretions; gallbladder contraction; Sphincter of Oddi relaxation; inhibits gastic emptying
How: IP3,Ca |
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Term
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Definition
Where: G cells of stomac
Why: small peptides and amino acids; stomach distention; vagal stimulation; GRP; secretin inhibiton
What: H+ secretion
How: IP3,CA |
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Term
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Definition
Where: S cell of duodenum
What: inhibit gastrin; NaHCO3 secretion
How: cAMP
Why: H+ and FFA |
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Term
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Definition
| parasympathetic; increases peristalsis and secretion; relaxes sphincters |
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Term
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Definition
| decreases peristalsis and secretion; contracts sphincters |
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Term
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Definition
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Term
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Definition
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Term
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Definition
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Term
| VIP (vasoactive intestinal peptide) |
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Definition
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Term
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Definition
| amino acid - Na symports or facilitated diffusion |
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Term
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Definition
At lumen: glucose and galactose with Na; fructose facilitated
At blood: GLUT2 |
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Term
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Definition
| Bile salt micelle with Chol, MG, LysoPL, and FFA--resterfication---formation of chylomicron--exocytosis into lymph (thoracic duct) |
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Term
| vitamin and mineral absorption |
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Definition
Fat soluble vitamins: chylomicron
Water soluble: Na cotransport
Iron: transferrin, ferritin
Calcium: calbinden controlled by Vitamin D |
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Term
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Definition
Small intestine: 1.5 L; Cl- secretion
Pancreatic juice and bile: 3 L
Gastric: 2 L
Diet: 2 L
Reabsorped: 8 L |
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