Role of hepatocytes in anabolic vs. catabolic states
anabolic - hepatocytes store energy rich nutrients from portal circulation
catabolic - hepatocytes release glucose from glycogen/gluconeogenesis into the systemic circulation
How do hepatocytes make glycogen?
*hepatocytes also import a.as for hepatocyte and plasma protein synthesis
How does glycogenolysis occur in hepatocytes?
When does ketogenesis occur?
Describe the Cori Cycle
Lactic Acidosis
What are the plasma proteins made in the liver?
How are plasma proteins made in the liver regulated?
Storage of nutrients in the liver
Lipid Metabolism
Diff between chylomicrons, VLDLs, LDLs, HDLs
Chylomicrons - intestine generated, deliver TGs to tissues, remnants deliver cholesterol to the liver
VLDLs - export TGs and cholesterol from liver to tissues
LDLs - derived from LDLs after they deliver TGs
HDLs - reverse transport of cholesterol from tissues to liver
Ammonia (NH4)
Bilirubin
- explain metabolism
3 Categories of Jaundice Causes
pre-hepatic (unconjugated) - hemolysis, hematoma, inherited metabolic abnormality
hepatic (conjugated) - viral, drug, alcohol, cirrhosis, Gilbert’s
cholestatic (conjugated) - sex hormones, gallstones, bile duct or pancreatic cancer, drugs, alcohol, viral, sepsis, PBC
Heaptic Metabolism of Drugs
Bile
- production
- 3 main functions
- composition
Bile salts
Risks for gallstone disease
Definition of:
Cholelithiasis
Choledocolithiasis
Cholecystitis
Cholangitis
Biliary Colic
Signs and symptoms of gallstones in the gallbladder vs. in the common bile duct
Gallbladder - asx, dull URQ/epigastric pain, nausea, diaphoresis, vomiting, fever, leukocytosis
- can see gallstones and sludge on U/S
CBD - fever, jaundice, pain, increased bilirubin/lipase/amylase/AST/ALT, mental changes, acute pancreatitis
- may see intrahepatic duct dilation on U/S along with gallstones and sludge in CBD
Which tests are more helpful for cholelithiasis vs. choledocolithiasis?
Cholelithiasis - HIDA scan helpful for cholecystitis, U/S
Choledocolithiasis - MRCP helps with anatomy and stones, ERCP helps with dx AND tx of stones
*only 10-15% of all gallstones have enough calcium to be visible on x-ray
Pros and Cons of U/S and CT for gallstones
U/S pros: cheap, no radiation, high sp/sn, can detect 1.5-2mm stones
U/S cons: operator dependent, scarring can lead to false negatives, can miss stones under 3mm, poor sensitivity in distal CBD
CT pros: useful to rule out other Dx, assess complications like perforation/cancer
What would you see on CT for acute cholecystitis? What is considered a dilated CBD on U/S?
HIDA Scan
MRCP
ERCP
HIDA Scan - use if diagnosis is unsure after U/S
- technetium label HIDA is IV injected and taken up via hepatocytes –> excreted into bile (allows tracing)
MRCP - magnetic resonance cholangiopancreatography and MRI with liver contrast
- helps evaluate biliary tree, non-invasive, no radiation
- good for CBD stones if no ECRP available or cancer
ERCP - scope, can diagnose and remove CBD stones
- can help stent and brush the CBD to rule out cancer
- could lead to bleeds, perforation, pancreatitis