gall bladder and bile Flashcards
What are the sources of blood supply to the liver
hepatic artery- 25%
hepatic portal vein- 75%
hepatic vein
what nutrients can the liver metabolize
carbs, proteins, lipids
What nutrients can the liver synthesize
plasma proteins, albumin, glucose, cholesterol, fatty acids, lipoproteins
what nutrients can the liver store
glycogen, fats, irons, copper and vitamins
what type of compunds is the liver good for detox
endogenous compunds like steroids
exogenous compounds like drugs and toxins
What are the specialized phagocytes in the liver
Kupffer cells
What compunds can the liver activate
Vit D
deiodination of thryoid hormone T4->T3
can the liver produce bile
yes
what is the gall bladder responsible for bile
storage, concentration and acidification
why is bile greenish yello
bilirubin
what molecules are found in bile
salts, proteins, cholesterol, hormones, enzymes and bilirubin
what is bilirubin a breakdown product of
hemaglobin
what causes jaundice
abnormally high levels bilirubin in the blood
What is a liver lobule
functional units of liver, hexagonal arrangement surrounding a central vein with a hepatic a, portal vein and bile duct at each 6 corner
what is a liver sinusoid
expanded capillary space between rows of hepatocytes
each hepatocyte is in contact with what two passages
sinusoid and bile cannaliculus
describe path of bile
hepatocyte->bile canaliculus->bile duct->common bile duct->duodenum
Majority of the liver parenchyma is what
95% hepatocytes
where are kupffer cells found
in the sinudoidal space
What cells are in the spaces of Disse
stella cells, plasma solutes, kupffer cells
What is a portal lobule
all hepatocytes drained by a single bile ductule
Describe mergence of the biliary tree
bile canaliculi merge with terminal bile ductules->pertubular ducts-> interlobular ducts merge with septal ducts->lobar ducts->R and L hepatic duct
Where is the sphincter of Oddi
on the hepatopancreatic ampulla
Describe the 2 stages of bile secretion in liver
1) hepatoctes through normal passage
2) secretory epithelial cells in the ducts and ductules that secrete water solution with Na and HCO3 as well as bile
stimulate by secretin
How would you describe the secretion of canalicular bile
active and isotonic
How much of the bile synthesized is diverted to gallbladder
50%
describe the bile that reaches the duodenum
dilute hepatic bile
concentrated gallbladder bile
Desribe the flow of ions from gallbladder
Na secreted actively which co transports K, Cl, H2O
The liver converts cholesterol into what
cholic acid and chenodeoxycholic
Where are bile acids dehydroxylated
in the terminal ileum
what are the secondary bile acids
deoxycholic and lithocholic acid
Most of primary bile salts are conjugated into what by hepatocytes
glycine and taurine
sometimes sulfate or glucoronate
What is the composition of fecal bile salts
majority is deoxycholic and a~30% lithocholic
describe the composition of biliary bile salts
45% cholic, 40% chenodeoxycholic and then like
15% desoxycholic
are bile acids in feces conjugated or deconjugated
deconjugated
What are the bile salts
cholates, chenodeoxycholate, deoxycholate
What is the role of bile salts in the bile
dissolve dietary fat
What are the fat soluble Vit
ADEK
Disruption of bile excretion can lead to what
malabsorption, diarrhea, steatorrhea and deficiencies in Vit ADEK
What is the role of bile phospholipids
enhance choelsterol solubizing properties
Inefficient excretion of cholesterol can lead to what
increased serum cholesterol
What are the 4 major components of bile
bile salts, cholesterol and phospholipids, bilirubin and protein.misc components
What are the 2 main funcitons of bile
fat digestion and absorption
waste product excretion
What is menat by enterohepatic circulation of bile
re-use, bile gets recycled back to the liver
What does bile help excrete
bilirubin, cholesterol, lipophilic drugs, trace minerals
What are the 2 actions of bile salts in intestinal tract
1) detergent action or emulsification on fat particles by decreasing SA and increasing agitation of the intestinal tract
2) absorption of FA, monoglycerides, cholesterol, lipids by forming small complexes called micelles
What is the calculation for total bile flow
canalicular flow + ductular flow
what is canalicular flow
independent flow + dependent (increases with bile secretion)
What is ductular flow
constant from cholangiocytes into bile ducts
What determines independent flow for bile
presence of organic compounds and osmotic force
ex: glutathione increases osmotic driving force for canalicular bile formation
What determines dependent flow for bile
depends on negatively charged bile salts, in micellar form and out of solution- have low osmotic force
What is a choleretic and give examples
something that stimulates release of bile, Secretin, glucagon, VIP and GRP
What is the result of somatostatin on bile release
enhances fluid absorption or inhibits secretion
How do secretin, glucagon, VIP and GRP increase secretion of bile
raise cAMP and stimulate apical Cl and Cl-HCO3 transporter
a Ca dependent Cl also gets activated
How does somatostatin inhibit bile flow
lowering cAMP, increase fluid reabsorption could cause this
What is the role of mucus secretion in gallbladder
protection from bile salt toxicity
What could too much mucus lead to
cholesterol cholelithiasis (cholesterol gallstones) marked by increase of mucin release
What is the result of CCK on gallbladder
contraction of gallbladder
relaxation of sphincter of iddi
increase bile flow
what sitmulates CCK release
presence of Fatty foods in duodenum
When the vagus N and intestinal enteric NS stimulates Ach release what happens
gallbladder is stimulated (not as strong as CCK)
Where are most of the bile salts reabsorbed
terminal ileum and return via hepatic portal vein
What percent of bile salts are lost each day in the stool
5%
Of the bile salts reabsorbed in the lumen how much is by diffusion and how much by active transport
half in early SI is diffusion
half in late digestions through distal ileum
Where do recycled bile salts first enter in liver
venous sinusoids
Ingestion of supplemental bile salts can do what to bile secretion
increase by several hundreds milliliters per day
The gallbladder can carry what strain of salmonella
salmonella typhi, typhoid fever
What is cholestasis
suppression of bile secretion
What does cholestasis cause
regurgitation of bile components into systemic circulation–>jaundice and pruritus (itching)
damaged hepatocytes release liver enzymes (alkaline phosphotase)
lipid digestion and absorption may be impaired
obstucting extrahepatic ducts or impairing flow in intrahepatic ducts may lead to what
cholestasis
What is cholelithiasis
formation of stones in gallbladder or biliary duct sytem
what is cholecystitis
inflammation of gallbladder
what is cholangitis
inflammation of biliary ducts
What can cause gall stones
abnormal bile composition (too much absorption of water from bile, too much absorption of bile acids from bile, too much cholesterol)
biliary stasis
inflammation of gallbladder
What are risk factors for cholesterol stones
female sex hormones, obesity, rapid weight reduction, gallbladder stasis, hyperlipidemia
What are risk factors for the pigmented gall stones
asians usually, chronic hemolytic syndromes, biliary infection, GI disorders like crohn disease or CF
What are the 4 contributin factors to cholelithiasis
supersaturation, gallbladder hypomotility, crystal nucleation, accretion within mucous layer
What is the Tx for gallstones w/o symptoms
nothing
what is the Tx for typical gallstones and symptoms
cholecystectomy
what is the Tx for atypical symptons for gallstones
search for related cause of symptoms
In a patient with typical biliary symptoms but no gallstones what should you Dx
suspicion for gallstone disease should be maintained
what percentage of people with gallstones is asymptomatic
70-80%
Which size of gallstones is the most dangerous
the small stones because they can tracel to enter cystic or common duct for obstruction
Someone with cholelithiasis is increased risk for what
carcinoma of the gallbladder
Symptomatic patients of cholelithiasis have what type of pain
biliary or colic pain
