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

...

FUNCTION OF SMALL INTESTINE

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enzymes within the enterocyte

...

several enzymes and hormones, are released by panceas into the SI

...

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