Liver Flashcards
How does the liver help maintain blood glucose levels?
After a meal, hepatocytes take up glucose and make glycogen (also takes up amino acids and makes proteins) Between meals it breaks down glycogen and releases glucose
___% of bile acids are reabsorbed in the intestine and recirculated
90%
How does unconjugated bilirubin become conjugated in order to be excreted?
Hemoglobin -> Heme -> biliverdin -> unconjugated bilirubin (lipid soluble) + _____ + _____ ->conjugated bilirubin excreted with bile
Albumin in the plasma and glucuronic acid in the hepatocytes in the liver makes conjugated bilirubin (water soluble)
Is fibrosis reversible in the liver?
No, fibrosis is an irreversible consequence of hepatic damage and has lasting consequences on patterns of blood flow and perfusion of hepatocytes
What do elevated ALT and AST mean?
A liver cell dies and spills its guts into the blood
Normal is under 50, elevated levels mean the liver cells are dying, liver injury
These are hepatocyte integrity labs
What are elevated alkaline phosphatase and GGT indicative of?
These are biliary tract integrity labs
Alk phos is found in the liver and bone. So if it is elevated, look at the GGT, a specific lab to the biliary tract, to see if it is a bone or biliary problem.
How can you determine a level of unconjugated bilirubin using total and direct bilirubin levels?
Direct is conjugated. Total is conjugated and unconugated.
Total - direct = unconjugated
If albumin is low, does that mean there is a liver issue?
Not necessarily, but if albumin and total protein levels are low, that is a liver problem!
How does prothrombin time relate to the liver? What about ammonia and the liver?
The liver makes clotting factors, with liver dysfunction, time will go up before clotting.
Ammonia also goes up with liver dysfunction, it can’t filter the toxins.
With liver disease, will albumin, ammonia, and glycemia levels be hyper or hypo?
Hypoalbuminemia
Hyperammonemia
Hypoglycemia (liver can’t break down glycogen and release glucose between meals)
What are other signs of liver disease?
Jaundice, cholestasis
Fetor hepaticus (breath of death, liver can’t dump stuff to biliary system, so it excretes in the lungs)
Hypogonadism, gynecomastia (liver can’t get rid of steroid hormones, estrogen raises, FSH/LH fall, less stimulus in gonads)
Palmar erythemia, spider angiomas (estrogen relaxes capillary beds, inc blood flow)
Weight loss, muscle wasting
What are signs of portal hypertension?
Ascites, esophageal varices, hemorrhoids, caput medusae, splenomegaly
Inc interstitial pressure causes edema of the GI (ascites)
The three portal systems that blood backs up to are rectum, lower esophagus, and umbilicus
List life-threatening complications of liver disease
Multiple organ failure Coagulopathy Hepatic encephalopathy Hepatorenal syndrome Esophageal varices rupture Hepatocellular carcinoma
Jaundice (excess bilirubin in the blood): causes?
- Increased unconjugated bilirubin (lipid soluble, bound to albumin, not excreted): excess bilirubin production, reduced hepatic uptake, impaired conjugation. Note: unbound plasma fraction diffuses into tissue (brain), toxic injury
- Increased conjugated bilirubin (water soluble, not bound, excreted by kidney): decreased hepatocellular excretion, impaired bile flow
Cholestasis features of hepatocytes?
Hepatocytes are enlarged, contain apoptotic cells, and kupffer cells have bile pigments (regurgitated)
Obstructed portal tracts can cause edema, bile retention, and neutrophilic inflammation
Hepatocytes are swollen and undergoing toxic degeneration
