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Block 3
Week 1
38
Agriculture
Pre-School
01/22/2009

Additional Agriculture Flashcards

 


 

Cards

Term
What is the cephalic phase?
Definition
Seeing and tasting food activates parasym efferent pathway stimulating secretion of gastrin, HCL, and motility.
Term
What is the gastric phase?
Definition
Amino acids and peptides in the stomach as well as stomach distention and caffeine stim gastrin and HCL
Term
What is the intestinal phase?
Definition
Distention, acidity, digestive products stim extrinsic and enteric system as well as secretion of secretin, CCK, and GIP
Term
What is the difference between extrinsic and intrinsic (enteric) system?
Definition
Extrinsic is composed of parasym and sym autonomic nerves, intrinsic is the local neural network of the bowel system.
Term
What controls the secretion of saliva, parasym, sym, or hormones?
Definition
Parasym facial and glossopharyngeal nerves and Sym T1-3 spinal nerves, but no hormones.
Term
True or False: The frequency of the basal electric rhytym (BER) of the caudad region of the stomach is regulated by neural and hormonal inputs.
Definition
False, the BER frequency is not regulated by anything, but the frequency of action potential firing during BER plateau is increased by parasym, gastrin, and motilin and decreased by sym activity that hyperpolarizes the membrane potential.
Term
What does CO2 have to do with HCL secretion in the stomach?
Definition
CO2 and water are changed to HCO3 and H+ inside the cell via carbonic anhydrase, the H+ is excreted via H/K ATPase and HCO3 is excreted basolaterally via a HCO3/CL channel while the Cl is excreted into the lumen to make HCL.
Term
What vitamin is modified by intrinsic factor from parietal cells so that it can be absorbed in the small intestine (ileum)?
Definition
B12, which is necessary for RBC production.
Term
When you need to vomit what part of the brain do neural inputs act on to induce vomiting?
Definition
Vomiting center of the brainstem medulla.
Term
What 3 qualities of chyme in the duodenum reduces the rate of gastric emptying?
Definition
High acidity has neural relflex to close pyloric sphincter, high fat releases CCK, and hyperosmolarity also closes pyloric sphincter
Term
What is a migrating myoeletric complex and when does it occur?
Definition
It occurs during fasting when motilin is released and it clears contents of stomach and small intestine and maintains a low bacterial count in large intestine. 1x/90min.
Term
How does the release of secretin and CCK from the small intestine affect the pancreas?
Definition
Both hormones enter the bloodstream which increase HCO3 and enzyme secretion, respectively.
Term
What percent of bile salts, which solubilize fats, are recycled?
Definition
95%
Term
When referring to GALT, what is a Peyer’s patch?
Definition
Lymphoid tissue in the small intestine (concentrated in the terminal ileum) that contains 5 lymphoid follicles that accumulate T/B/Macrophage cells and are covered by mucosal epithelium.
Term
How do intraepithelial lymphocytes and epithelial cells function in GALT?
Definition
IELs are located in the gut and lamina propria and consist of CD8 T cells that secrete cytokines, and epithelial cells act as antigen presenting cells.
Term
There are diffuse accumulations of lymphoid cells in GALT, what two cell types predominate?
Definition
Intraepithelial lymphocytes and lamina propria cells (mononuclear cells, IgA producing plasma cells, mast cells, etc.)
Term
What is the role of IgA in the GALT?
Definition
It is a non-inflammatory molecule that prevents molecule uptake and can also expel molecules from cells.
Term
What is oral tolerance?
Definition
Suppression of immune system despite the presence of antigen-activated mucosal immune response and production of gut IgA
Term
What does a food allergy have to do with IgE?
Definition
When there is a breakdown of oral tolerance, the body makes IgE instead of IgA that bind with food antigen. The IgE’s then bind with mast cells in lamina propria which, once triggered upon second ingestion of allergen, release chemicals that increase chloride secretion and diarrhea. A mucosal response can trigger colorectal distention.
Term
How are zymogens activated?
Definition
Pancreas releases trypsinogen that is activated by enterokinase in intestinal lumen and then becomes trypsin; trypsin activates all other zymogens.
Term
If a baby gets diarrhea when they drink breast milk, what affliction do they have?
Definition
Glucose-Galactose malabsorption
Term
Why does a person’s breath hydrogen increase if they have lactase deficiency?
Definition
Colonic bacteria metabolize the uncoverted lactose and release H2.
Term
What percent of fluid is absorbed by the GI tract?
Definition
99%, 82% from small intestine, and rest from large intestine.
Term
Where is the majority of final carb digestion occurring in the GI?
Definition
Proximal jejunum.
Term
True or false: A healthy adult consumes 250g of carbs, 50g of complete protein, and 60-160 grams of fat.
Definition
TRUE
Term
Which molecules does lactase, amylase, sucrase, and glucoamylase create in its final product?
Definition
Glucose, fructose, and galactose
Term
What key pancreatic enzyme allows for the activation of all other digestive enzymes?
Definition
Enterokinase in duodenum brush border; it activates trypsin which activates chymotrypsin, elastase, and carboxypeptidases
Term
How are glycerol, short/medium chain fatty acids absorbed differently than micelles made of cholesterol, long chains, and monoglycerides?
Definition
First group passes through enterocytes and enter capillary, second group absorbs through SER then golgi as a cholymicron then enter lymphatic capillary called lacteal
Term
What is the main source of 5-HT in the GI?
Definition
Enterochromaffin (EC) cells and internuerons make up 95% of the body's serotonin; EC is the major source in the intestine
Term
What is the serotonin (5-HT) precursor that can be ingested?
Definition
Tryptophan; most other 5-HT sources are metabolized before entering blood
Term
How is 5-HT serotonin metabolized?
Definition
Enterocytes only on the intestinal epithelium transport it into cell via Serotonin Reuptake Transporter (SERT) and metabolized to 5-HIAA and then is pissed out; or metabolized by lungs, liver MAO enzyme to 5-HIAA
Term
There are 4 places in the periphery that serotonin is located - lungs, blood platelets, plasma, EC cells in gut - where is the content high or low?
Definition
Lungs/plasma= low, EC cells/platelets= high
Term
True or False: platelets and lungs maintain high blood levels of 5-HT by adding it to the circulation.
Definition
False, they maintain low levels in the blood since platelets store it to use for aggregation and the lungs metabolize it. Therefore peripherap 5-HT has a major role in regulation of GI motility.
Term
What is the difference in communication effects between 5-HT3 and 5-HT4 receptors?
Definition
Both receptor types increases IPAN (intrinsic primary afferent neurons) firing of Ach at the synapse with myenteric neurons when EC cells are triggered, but only 5-HT3 receptors also increase communication to the CNS
Term
True or false: The brain-gut connection illustrates that both a suppressed immune system and IBS can be attributed to emotional state.
Definition
TRUE
Term
Describe the route of transmission for Hep A, B, and C. Also describe if there is a chronic carrier state
Definition
Hep A - oral-fecal, self-clearing; Hep B sexual, vertical, blood transmission, more common with MSM, self-clearing; Hep C blood exposure, not sure if sexually transferred, chronic condition.
Term
True or False: women are more likely to suffer alcoholic cardiomyopathy and progress to alcoholic liver disease earlier than men.
Definition
true
Term
Histamine stimulation can be induced by both a neuronal pathway and hormonal pathway via the ECL cell, describe which molecule is used for each.
Definition
Ach is used to activated muscarinic receptors to move Ca mediated exocytosis on the ECL; Gastrin will activate CCK2 receptors on ECL as well
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