biliary tree and gal gallstones and biliary tree x

Question Answer
what's cholecystitis? inflammation of gallbladder
what's cholelithiasis? gallstone (within gallbladder)
what's cholecystectomy? removal of gallbladder
what's choledocholithiasis? gallstone within bile duct
what's cholangitis? infection of bile duct
what's mrcp? magnetic resonance cholangiopancreatography
what's ercp? endoscopic retrograde cholangiopancreatography
what's ptc? percutaneous transhepatic cholangiography
what does the common bile duct pass behind? duodenum
what does the common bile duct pass through? through the head of the pancreas – joins with main pancreatic dut
what does the common bile duct open into? 2nd part of duodenum (ampulla of vater)
what's the flow of bile regulated by? sphincter of oddi (smooth muscle)
what does the gallbladder act as? reservoir for bile – 30-ml capacity
where does the gallbladder lie? in gallbladder fossa on inferior surface right lobe liver
how many anatomically defined regions does the gallbladder have? 3
what is the gallbladder connected to the common hepatic duct/common bile duct by? cystic duct – 2.5cm ength
what sort of lining does the gallbladder have? columnar epithelial lining
what does the gallbladder do to bile? concentrates it (water and salts reabsorbed)
list the components of bile bile acids, water, electrolytes, cholesterol, phospholipids, conjugated bilirubin
what is bile acid synthesised from and where? synthesised from cholesterol – multistep process in hepatocyte
what are the two main primary bile acids cholic acid and chenodeoxycholic acid are the main primary bile acids
how can the two main primary acids be conjugated to secondary bile acids? conjugated to secondary bile acids by addition of amino acid group (taurine or glycine) before active export from hepatocyte
what can produce intestinal bacteria action of intestinal bacteria can produce secondary bile salts by de-hydroxylation
what causes gallbladder contraction? vagal stimulation
what is released from the duodenum in response to presence of luminal fat? Cholecystokinin (CCK) released from duodenum in response to presence of luminal fat
what promotes release of bile juice in to duodenum? CCK mediated GB contraction and relaxation of sphincter of Oddi x
What is gallbladder relaxation and closure of the sphincter of Oddi mediated by? sympathetic nerves, and gut hormones vasoactive intestinal polypeptide (VIP) and somatostatin
Give four functions of bile acids promote intestinal absorption of fats by emulsification and formation of micelles, enhance absorption of fat soluble vitamins, facilitate excretion of cholesterol, exert hormone like effect to influence intestinal metabolic pathways
why are bile salts more effective than bile acids at promoting intestinal absorption? because they are amphipathic – they are both hydrophilic and lipophilic moieties which improves ability to emulsify
how do bile acids facilitate excretion of cholesterol? by solubilising cholesterol within bile and by being a product of cholesterol metabolism
what happens to 95% of bile acids? They recirculate via enterohepatic circulation – total pool of bile acids circulates 6-8 x/day
where does reabsorption of bile acids take place? mainly in ileum/terminal ileum by active transport into portal circulation
where is bile synthesised and why? synthesis of new bile acids in the liver compensates for faecal loss
how are hydrophobic bile acids transported? bound to albumin in the blood to facilitate transport back to the liver
what does venous blood from the ileum feed into? venous blood from the ileum feeds into the portal vein and then directly to the liver sinusoids
what percentage of people with gallstones are asymptomatic? approximately 80%
what % of pop have gallstones on USS scanning? 7-15%
5Fs for risk factors of gallstones x female, fair (white), fertile (preg), forty, fat. increasing incidence with age
name two other things that are risk factors for gallstones x diet (low fibre), inflammatory bowel disease
name the three main events that lead to gallstone formation cholesterol supersaturation, biliary stasis, increased secretion of bilirubin
what can cause cholesterol supersaturation? cholesterol is solubilised by bile but high levels of cholesterol lead to supersaturation
when does cholesterol supersaturation typically occur? when oestrogen levels are high – e.g. obesity, pregnancy, OCP, liver disease, and when bile acid levels are low – e.g. following small bowel resection or in active crohns when enterohepatic circulation is ineffective
when does biliary stasis occur? during periods of fasting or starvation. observed during prolonged total parenteral nutrition
when is bilirubin soluble? IN bile following conjugation with glucuronide (i.e. conjugated bilirubin)
when can pigmented stones develop? increased RBC breakdown – especially haematological conditions (e.g. sickle cell), malaria, valvular heart disease, post chemotherapy, failure of hepatic conjugation
list some gallbladder complications of gallstones biliary colic, acute cholecystitis, empyema, cancer, mucocoele
list some complications in common bile duct of gallstones obstructive jaundice, cholangitis, pancreatitis
what gallstone complications happen in small intestine gallstone ileus
what is biliary colic? when pain occurs due to a gallstone temporarily blocking the bile duct
where might u feel the pain with biliary colic pain in epigastrium/right upper quadrant, through to back
what is biliary colic usually provoked by? eating as it leads to gallbladder contraction
name the three types of gallstone cholesterol stone, bile pigment stone, mixed stones
describe cholesterol bile stones usually solitary, oval, and large (up to 3cm)
describe bile pigment stones multiple, irregular, hard, associated with chronic haemolysis (e.g. sickle celL)
Describe mixed stones most common stone type (80%), multiple, multi-faceted, laminated structure with layers of cholesterol, bile pigment, and calcium salts
whats common with biliary colic and what doesn't it cause vomiting common but it doesn't cause jaundice or fever. often settles if stone moves back in to the gallbladder body/fundus
what happens if biliary colic is recurrent cholecsytectomy
whats acute cholecystitis inflammation of the gallbladder that develops over hours, usually because a gallstone obstructs the cystic duct. impacted stone in gallbladder leading to GB wall oedema/inflammation and development of bacterial infection within GB wall
give symptoms of acute cholecystitis pain, nausea, vomiting, fever, abdominal tenderness. raised inflammatory markers, sometimes abnormal LFT plus or minus with jaundice
how do u treat acute cholecystitis antibiotics, analgesia, elective cholecystectomy when symptoms settle
give two common causes of posthepatic obstructive jaundice choledocholithiasis and pancreatic cancer (in head of pancreas compressing common bile duct)
give some less common causes of posthepatic obstructive jaundice pancreatitis (swelling of pancreas gland compressing common bile duct), benign bile duct structure, portal lymphadenopathy, cholangiocarcinoma (cancer of bile tube)
list some signs and symptoms of obstructive jaundice pale stools, dark urine, yellow sclerae, itch (and scratch marks), features of chronic liver disease, abdominal tenderness/palpable gallbladder?
what's choledocholithiasis? presence of gallstones in common bile duct. migration of one or more stone from GB to bile duct
where does choledocholithiasis impact? above ampulla of vater where duct narrows significantly
what might choledocholithiasis present with? obstructive jaundice (usually with pain), cholangitis, acute pancreatitis, combo of above
what's needed for cholangitis? antibiotics
what can you do to attempt stone removal? ERCP to attempt stone removal – incision at sphincter of Oddi to increase duct diameter, extract stones with balloon or basket
what can prevent recurrence of choledocholithiasis cholecystectomy to prevent recurrence
where is pancreatic cancer most common? in head of pancreas gland – compresses common bile duct as it passes through pancreatic tissue
how can u treat obstructive jaundice caused by pancreatic cancer? ERCP and stent provides drainage of bile, relief of jaundice, bridge to chemotherapy
what's AST/ALT? hepatocyte enzymes (AST also found in cardiac muscle cells)
What's ALP/GGT associated with? associated with bile duct cells but different isoenzyme of ALP also produced in bone
What does alkaline phosphatase do? enzyme that transports metabolites across cell membranes. Is present in bile duct epithelial cells, therefore biliary stasis = release of the enzyme
where is alkaline phosphatase mainly found? liver and bone
where else is alkaline phosphatase found? Intestine, placenta, kidney
where is bilirubin found? serum and liver
what factors does prothrombin time assess? Factors I, II, V, VII, and X
what happens to ALP in biliary obstruction? Increases early – often up to 10x ULN. Often associated with rise in GGT
What happens to bilirubin during biliary obstruction? rises steadily and level of bilirubin is indicative of duration of obstructive process
when can AST?ALT be elevated? in obstructive jaundice but much less prominent and often more transient
what is common in prolonged obstructive jaundice? coagulopathy
what is elevated in obstructive/cholestatic pathology? ALT, AST, ALP, GGT, Bilirubin

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