Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
8 Cards in this Set
- Front
- Back
|
What is bile?
|
- Bile is the important digestive secretion of the liver
- About 0.7-1.2 litres produced in a day Major roles - alkali to neutralise gastric juices - Substance to faciliate absorption of fat - Vehicle to aid excretion of liver products |
|
|
What is bile comprised of?
|
Bile acid-dependent fraction
- Bile acids are water soluble derivatives of cholestrol (glycocholic acid and glycochenodeoxycholic acid)(What role?) Bile acid-independent fraction - HCO3- rich fraction and H2O (What role) Bilirubin breakdown products |
|
|
What are the key components of a liver lobule?
|
Central vein
Sinusoids Space of Disse Terminal lymphatics Portal vein Hepatic artery Bile duct Liver cell plate Littoral cell (Kupffer cell) Bile canaliculi Lympatic duct |
|
|
How is bile made?
|
Bile acid-dependent fraction
- Production of bile acids by liver cells, also recirculation of bile from blood. Conjugation necessary to make H2O soluble. Made during the final stages of digestion Bile acid-independent fraction - Alkaline and isotonic - under the influence of secretin (acid chyme reaching duodenum) |
|
|
What happens to bile?
|
- Bile directly secreted into duodenum or taken up into the gall bladder.
- In the gall bladder there is significant concentration of the bile (removal of H2O and NaCl) - Gall bladder store of bile secreted in response to meal (cholecystokinin CCK) - significant reabsorption of bile from ileum |
|
|
What is the enterohepatic circulation?
|
- 90% of bile is recirculated through the portal circulation
- unconjugated bile acids cannot be reabsorbed - Breakdown of bile acids in ileum by bacteria - excreted in faeces. |
|
|
The circulation of bile Acids
|
Liver
Cholesterol --> (chenodeoxy-) cholic acids --> taurine conjugation ==> Gall bladder (empties on feeding) ==> Duodenum ==> Ileum --> 10% faeces ==> 90% portal circulation --> 5% systemic circulation ==> 95% Back to liver |
|
|
What are some questions to do with bile?
|
What might be the consequences of interruption of bile acid production or secretion into the gut? (steatorrhoea)
Will gall stones be radio-opaque? What sort of meal will produce the greatest amount of gall bladder contraction (biliary colic)? |
