midter, 1, part 3, set 2
composition of bile synthizedby liver
complex fluid containing water, electrolytes and several organic moleculles including bile acids, cholesterol, phospholipids anda bilirubin, that flows through the binary track into the small intestine
cholic acid plus glycine give?s
glycocholic acid
chenodoxycholic acid plus glycine
glycoendeoxycholic acid
procarboxypeptidase
neural amino acids
DUODENUM- SITE FOR:
neutralization of acids. emulsification of fats secretion of pancreatic juices
present in bile as bile acids
the acids
when micel is formed?
when bile acids/ bile salts/ along with phosholipids absorb lipids, a micelle is formoed
ENTEROHEPATIC CIRCULATION
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FUNCTION OF SMALL INTESTINE
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enzymes within the enterocyte
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several enzymes and hormones, are released by panceas into the SI
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how many g is syntetized by liver daily
.5g
alpha-amylase attacks which glycosidic bond of starch?
1-4
1. emulsification
1. detergent action on fat particles, which causes fat globules to break down into minute droplets. 2. emulsification is not digestion per se, but it increases the surface area of fat, making it available for digestion by lipase, which can not access the inside of lipid droplets
2 functions of bile
1. emulsification of lipid aggregates 2. solubilization and transport of lipid in an aqueous environment
2. solubilization and transport of lipids in an aqueous environmetn
1.bile acids are lipid carriers and are able to solubilize many lipids by forming micelles -aggregates of lipids such as fatty acids, cholesterol and monoglycerides- that remain suspended in water
during single digestive system
2-3 times
each bile salt molecule is reused how many time
20 times
how many bile salts it contain?
40 bile salts molecules
adults secrete how many ml of bile per day?
400-800
digest how many % of protein
50%
it digest how % of CHO?
50%
how many gr of bile salts enter SI daily?
50g
approximatelly xx% of the bile acids delivered to the duodenum are reabsorbed back into the blood within the ilium?
95%
acidic chyme entering the duodenum is neutralized by secretions releases by
BRUNNER'S GLANDS
this hormone stimulates contraction of the gallbladder and common bile duck, resulting in the delivery of bile into the duodenum
CCK
give definition: entering the duodenum with acids and partially digested fats and proteins stimulates secretion of CCK- cholecystokinnin and secretin
chyme
The strongest influence is the secretion ofCCK and secretin in response to the presence of food in the duodenum. CCK acts primarily on the acinar cells which produce a relatively small volume of fluid containing water, electrolytes and digestive enzymes. Secretin acts primarily on the ducts to produce a larger volume of bicarbonate-rich secretion. When both hormones are present they each amplify the other's effects in a phenomenon called potentiation.
The primary stimulus for the secretion of secretin is the acidity of the chyme entering the duodenum. Since secretin stimulates secretion of bicarbonate rich fluid this results in a decrease in the acidity of the chyme. This reduction in the acidity of the chyme is necessary for the proper functioning of the enzymes in the duodenum. The secretion of CCK is caused by the presence of fat and protein digestive products in the duodenum. CCK increases the secretion of enzymes by the acinar cells.
what is micelle?
a spherical, dislike compelex, containing as many as 40 bile salts molecules
which cells of pancreas, secrete
acinal cells
by bile duck
bicarbonate rich secreation goes to gallbladder- concentrated bile
what bile contains?
bile contains bile acids with detergent properties which are critical for digestion and absorption of fats and fat-soluble vitamins in the small instestine
what hepens in hepatocyte important
cholesterol goes to bile acids- cholic and chenodeoxycholic conjugation to glycine or taurine
gallstones are composed predominately of what?
cholestron, results from processes that allow cholesterol to precipitate from solution in bil
gall bladder
concentrate and store the bile until the bile is required in the duodeneum
what happens in CANNALICULI
conjugated bile acid
what lipase does?
digest most of the ingested lipids -90%
when is the flow of bile lowest?
during fasting it is diverted into the gallbladder for storage and concentration
what is the name? enzymes on the brush boarder
ectoenzymes
hepatocytes exctract bile acids very
efficient from sinusoidal blood and lite escapes into the systemic circulation
secretion of bicarbonate and water
expands the volume of bile and increases the flow into the intestine
what enzymes are found in brush boarder of the stomach?
isomaltase glucoamylase glucosidase maltase aminopeptidase dipeptidase tripeptidase
what is the function of glycocholic acid?
it is amphipathic has both polar and non polar ends
small intestine SI: secretion of water
large quantities of water are recreated into the lumen of the small instine during the digestive
trypsinogen/ trypsin, digest which aa?
lysine argenine
another a.a. that form conjugated bile
taurine
2. bile acids are also critical for transport and absorption of what?
of fat soluble vitamins
important: more bicarbonate is released from
pancrease
chymotrypsinogem/ chymotrypsin
phe, tyr. try met asn his
what the most potent stimulus for release of CCK ?
presence of fat in the duodenum
it stimulated biliary duck cells to secrete bicarbonate and water
secretin
secreted in response to acid in the duodenum
secretin
what is the major route for eliminating cholestrol?
secretion in bile, cholestrol is soluble by acids
gall bladder:
storage of bile
other:
to increase the concentratio of bile the gall bladder reabsorbes around 90% of water and electrolytes
what are proteolytic enzymes
trypsinogen chymotrypsinogen procarboxypeptidase proelase collaginase