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48 Cards in this Set
- Front
- Back
What do the duct cells of pancreas secrete?
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these secrete aqueous HCO3 rich solution
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Where are B cells, A Cells, and D cells all found?
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these are found in the islets of langerhans
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What do B cells secrete?
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insulin
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what do A cells secrete?
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glucagon
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what do D Cells secrete?
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somatostatin
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How does the SNS affect the pancreas?
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this inhibits pancreatic secretion (postganglionic via celiac and superior mesenteric plexuses)
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how does the PNS affect the pancreas?
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this stimulates secretion (via vagus)
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Where are pancreatic enzymes stored?
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in zymogen granules of acinar cells
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What are the 3 types of pancreatic enzymes secreted by Acinar cells?
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Pancreatic proteases
Pancreatic alpha-amylase Pancreatic Lipase |
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What two things activate Typsinogen? where do they come from? (ignoring autocatalysis)
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enteropeptidase and enterokinase from
duodenal mucosal cells |
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what does trypsin activate?
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chymotrypsinogen and procarboxypeptidase
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What is the major source of lipase?
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the pancreas
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what is steatorrhea?
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this is fatty stool, typically caused by Cystic Fibrosis
(or can be from a lack of lipase activity) |
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Why does acidic chyme in the duodenum need to be neutralized quickly?
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this prevents pancreatic enyzme from functioning properly, also can damage duodenal wall
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what is the largest part of pancreatic secretion?
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NaHCO3 (to neutralize acid, 1-2L a day)
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At basal rates of pancreas secretion, what are the 3 components of the aqueous alkaline secretion?
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Na and Cl and H20
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at stimulated rates of pancreas secretion, what are the 3 components of the aqueous alkaline secretion?
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Na and HCO3 and H20
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What does secretin release in response to? what secretes it? what does this do?
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this is secreted by S cells of duodenum in response to H+ in the duodenum
this induces the production of HCO3 rich aqueous secretion from the extralobular ducts (ductal cells) |
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What system primary controls pancreatic exocrine secretion?
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mainly hormonal
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what phase of digestion does most of the pancreatic secretion take place during?
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the intestinal phase
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Where are I Cells and S Cells found?
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in the duodenal mucosa
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What kinds of things stimulate I Cells? what do I Cells release in response?
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AA's (phen, Met, tyrp)
small peptides, fatty acids this releases CCK in response |
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What does CCK do to Acinar cells (after being released from I cells)
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this causes increased Ca2+, and a release of enzymes
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What does Secretin do to Ductal cells?
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this increases cAMP, this leads to an increase in aqueous secretion
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What causes chronic pancreatitis?
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booze
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what are the effects of chronic pancreatitis?
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fat malabsorption and diabetes
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What are the symptoms of pancreatic cancer?
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weight loss, abdominal pain, jaundice, fatigue, clay-colored stools, back pain
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what 3 things increase the risk of pancreatic cancer?
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older than 50
smoking, high caloric intake |
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What is the tonicty of pancreatic secretion?
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isotonic
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In a liver lobule, where does blood flow?
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this flows from portal vein or heapatic artery, and flows TO the central vein
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where are the bile duct located? what drains into them?
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these are located on the periphery of the liver lobule. Bile caaliculi drain bile out to them
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What two cell types are used to create bile salts?
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Bile from Bile Duct Cells
and Organic constituents from Hepatocyte activity |
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What are bile salts derived from?
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cholesterol
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what is the circulation of bile salts between SI and Liver called?
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enterohepatic circulation
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What do Bile salts do?
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these emulsify fats, used for lipid absorption
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Where does most absorption of bile salts take place?
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in the ileum
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what are the 4 major organic constituents of bile?
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bile salts
cholesterol lectihin bilirubin |
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What does the liver do with bilirubin?
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this actively removes it and secretes it into bile
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what is the major source of bilirubin?
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worn out RBCs being broken down, the heme part is what gives off bilirubin
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how does obstruction of the bile duct affect fecal color?
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this lowers the levels of bilrubin in it, and thus makes it lighter
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What is a choleretic?
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this is any substance that increases bile secretion by the liver
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What are the 3 major choleretic signals?
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Bile salts reentering the the liver
secretin vagus nerve (minor) |
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when does jaundice occur?
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when bilirubin production exceeds excretion
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what causes pre-prehepatic jaundice?
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more RBC's broken down than the liver can remove, too much bilirubin
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what causes hepatic jaundice
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diseased liver cannot deal with normal levels of bilirubin
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what causes post hepatic jaundice?
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this is caused by an obstructed bile duct, so bilirubin is not excreted
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whats the treatment for jaundice?
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photo therapy
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How many vessel types are on the outer edge of the liver lobule?
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heptaic artery, portal vein, bile duct
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