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24 Cards in this Set
- Front
- Back
- 3rd side (hint)
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Secretions are Added to food in the GI tract by what 3 things
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Secretory Epithelium, Pancreas, Liver
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Peptic Ulcer Risks
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Smoking, Excess alcohol, Black tarry stools, vomit red blood
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Sphincter of Oddi
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Tonically contracted, separates common bile duct from small intestine, allows passage of bile/pancreatic enzymes during a meal
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4 Layers of GI tract Wall
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Mucosae: faces lumen
Submucosa Muscularis Externa Serosa: CT covering (attached to mesentary sheet) |
Mucosa Contains Crypts/Gastric Glands (house stem cells) and Lamina Propria (CT, contains nerve fibers and Peyers Patches)
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Muscularis Externa Consists of...
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2 Layers of Smooth Muscle
1. Inner circular layer (contraction decreases lumen diameter) 2. Outter Longitudinal Layer (contraction shortens tube) -Also contains Myenteric Plexus (nerve network controlling Musc. Ext. motor activity) |
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GI Smooth Muscle Contractions are...
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*Spontaneous
-via gap junctions Tonic: Sphincters, anterior stomach Phasic: Posterior Stomach, Small Intestine |
Phasic=slow wave potentials
-Slow wave freq. varies by region (fastest in duodenum) ICC: pacemakers |
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Secretions....
1. Parietal Cells 2. Acinar Cells 3. Duct Cells |
1. HCl from gastric glands into stomach lumen
2. Digestive Enzymes from the pancreas (exocrine) 3. NaHCO3 from exocrine portion of Pancreas (HCO3- also secreted by duodenum)-CFTR Cl- channel |
Parietal Cells Pump HCO3- into the BLOOD, Duct Cells pump H+ into the BLOOD
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Hormones Secreted by Stomach/Intestine
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Stomach: Gastrin (stim gastric acid secretion)-inhibited by somatostatin
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CFTR cells are found where?
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Pancreatic Duct cells, Duodenal Cells, Crypt Cells of SI and Colon
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Saliva is made up of...
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water, ions, mucus, proteins (enzymes/IGs)
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Cystic Fibrosis Caused by (MOA)
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Defect in CFTR Cl- transporter does not allow Cl- secretion into lumen, therefore Na+ and H20 cannot follow and lumen mucus thickens=clogs sphincter of oddi
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Bile is...
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-nonenzymatic
-secreted from hepatocytes -stored in gall bladder |
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Bile Contains...
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Bile Salts: aid in fat digestion via emulsification
Bile Pigments: ie Bilirubin (Hb waste) Cholesterol+Drugs: (detoxifying) |
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CCK
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-promotes satiety
-neuropeptide (from neurons) -secreted as zymogen -stimulates gallbladder contraction+pancreatic enzyme secretion |
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Features ENS shares with CNS
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1.Intrinsic Neurons
2. NTs and Neuromodulators 3.Glial Support Cells 4.Capillary Diffusion Barrier 5.Integrating Center |
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Bilirubin
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Hb Waste Product
-reversibly binds to albumin in plasma ("free") -Liver removes bilirubin from plasma easily by esterifying it w/glucuronic acid=conjugated bilirubin=more soluble |
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Jaundice is...
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*Bilirubin Build up in ECF (yellow skin/sclera)
Caused by...^RBC breakdown, bile duct obstruction, Liver Damage |
Bilirubin+Ca2+ Salts=GallStones
(80% from cholesterol) |
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Iron Fate
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Trasported by Transferrin to Bone Marrow Fe--> Hb, then Hb moves to Spleen Hb-->Bilirubin, Bilirubin is then metabolized in the liver and excreted in urine and feces
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Nutrient Absorption in Small Intestine...
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Nutrient-->Cell-->Capillaries-->Hepatic Portal System
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Sjogren Syndrome
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AI Disease
-decreases secretions (saliva, tears) -No amylase (dry mouth/dry eyes) -Leads to teeth problems (no lysozyme for cleaning) |
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Pneumonia
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^gastric pH=more risk for bacterial infections like pneumonia
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2 Types of Diarrhea
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Osmotic Diarrhea: undigested lactose, stuff left in intestinal lumen=^osmolarity, fluid stays in lumen
Secretory (Choleretic) Diarrhea: caused by bacterial toxins that ENHANCE CL- SECRETION, water follows...(MORE SERIOUS) ex. Cholerae, E. Coli |
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Cells secreting Substances in Gastric Pit...
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D Cells: Secrete Somatostatin
Parietal Cells: Secrete Gastric Acid and Intrinsic Factor Chief Cells: Secrete Lipase and Pepsin G Cells: Secrete Gastrin Mucous Neck Cells: Secrete Mucous and Bicarbonate Enterochromaffin-like Cells: Secrete Histamine |
**Gastric Acid Activates Pepsin
EDC MPG |
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Fibrates work to decrease Cholesterol levels by...
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Stimulating PPAR-alpha and Niacin promoting cholesterol catabolism (Txn Factor)
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