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10 Cards in this Set
- Front
- Back
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There are 2 kinds of lipids. What are they and what do they include?
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1. Endogenous: (made from our own bodies) cholesterol, phospholipid, desquamated intestinal villus epi cells
2. Exogenous: (we have to eat these) triglycerols, cholesterol, phospholipids |
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What are the 5 processes involved in lipid assimilation
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1. secrete BILE and LIPASES
2. emulsifyyyyy 3. hydrolysis of ester linkages 4. solubilization of lipolytic products within bile salt micelles 5. transport in and out of enterocyte |
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What are the 6 lipases found in the digestive tract? Where are they located?
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MOUTH/all over: lingual lipase; food lipase
STOMACH: carboxyester lipase; gastric lipase(important for babies who have 0 pancreatic lipase & for Z-E) SMALL INTESTINE: bile, pancreatic lipase |
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The 2 hormones that stimulate pancreatic acinar cells thus stimulating pancreatic enzymes are....
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1. Ach
2. CCK |
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How can you overcome inhibition of pancreatic lipase?
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co-lipase
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What are the two things that pancreatic cells release?
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HCO3
H2O |
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3 lipases work in the intestinal lumen to break down lipids. what are they and in what form are they initially secreted? what do they do...?
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1. lipase breaks down TRIGLYCERIDE into 2 monoglycerides and fatty acids
2. phospholipase A2 breaks down phospholipids into fatty acid and lysolecithin (requires bile salts) 3. cholesterol esterase breaks down CHOLESTEROL ESTER into cholesterol and fatty acid (needs bile salts) they are secreted in their inactive forms; they get secreted with co-lipase; they get rid of steric hindrance (aka inhibition of bile salts) |
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Describe the role that bile acids and micelles play in lipid assimilation
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Bile acids:
Micelle: ferry lipids across unstirred water layer then they dump stuff. fatty acids will get reabsorbed. |
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What are the steps involved in getting lipids from brush border to outside of enterocyte?
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1. long FAs converted back into TGs, phospholipids, esters in SER
2. fat droplets get made in cisternae of SER 3. apoproteins made in RER go to SER and mingle with the lipid droplets 4. nascent chylomicrons and VLDLs arrive at 'cis' face of Golgi. apoproteins get glycosylated 5. vesicles carrying chylomicrons/VLDLs bud off from 'trans' Golgi and move to basolateral membrane 6. transport vesicles fuse to the membrane and releases chylomicrons and VLDLs. 7. chylomicrons and VLDLs pass through lymphatics 8. on another note, glycerol, short and med FAs pass through enterocyte and enters blood |
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What are some potential abnormalities in lipid assimilation?
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1. emulsification problem-rapid gastric empyting
2. pancreatic lipase problem-hyperacidity, obstruction, CF, chronic pancreatitis 3. bile salt micelle problem-bacterial overgrowth, bile acid prodxn bad, biliary obstructio 4. within enterocyte-a beta lipoproteinomeia (MTP) 5. inadequate surface area-celiac, bacterial/protozoan 6. lymphatic transport problem-Whipple's disease |
