Liver Function Flashcards
What is the function of the hepatic artery?
Aortic branch which provides oxygen to the liver.
What is the function of the portal vein?
Blood supply from the GI tract; transports absorbed materials.
Hepatocytes within the liver include what two types of cells?
Kupffer Cells and Sinusoids.
What is the function of Kupffer cells?
Phagocytosis of RBC’s.
Hepatocytes make up ___ of the liver’s mass.
80%.
What is the function of microvilli within hepatocytes?
Works in conjunction with sinusoid space; passes absorbed materials across the cell membrane.
What is the function of the smooth ER within hepatocytes?
Bilirubin conjugation; drug detoxification; cholesterol synthesis.
What is the function of the rough ER within hepatocytes?
Ribosome synthesis (protein production) which provide albumin, coagulation factors, and enzymes.
What is the function of the bile capillary within hepatocytes?
Excretes bile and waste products; acts as an outlet system.
The liver processes dietary and endogenous ___ for energy.
Carbohydrates.
How is carbohydrate metabolism effected by liver disease?
(1) Hypoglycemia
(2) Diminished tolerance to the administration of glucose, galactose, fructose, or lactose.
(3) Decreased glycogen stores.
What is one of the most important functions of the liver?
Bile synthesis.
What is the function of bile?
Lipid absorption and digestion.
Where is bile stored?
Within the gallbladder.
Fatty liver conditions are from the accumulation of ___.
plasma free fatty acids and lipoproteins; triglyceride accumulation.
How does the liver change in moderate severity of fatty liver (liver fibrosis)?
Scar tissue begins to form; recovery is possible, but scar tissue remains.
How do laboratory results change with someone who may have fatty liver?
Mild elevation of AST and ALT.
Severe or chronic hepatic diseases cause a decrease in what plasma proteins?
Albumin, fibrinogen, transferrin, and coagulation proteins.
Measurement of enzymes that are released after an injury are able to help differentiate between what two conditions?
Hepatocellular from obstructive disease.
What are the 5 most commonly measured enzymes for the liver?
AST, ALT, LDH, ALP, GGT.
How does the liver handle xenobiotics (nonmetabolic products)?
Converts to more soluble, less toxic compounds; toxic compounds are absorbed from the intestinal tract.
How do we get ammonia in the blood?
From the urea cycle; amino acid deamination.
If there is an increase in ammonia levels, how would this effect the body?
Highly toxic; may increase pH in the blood.
Which immunoglobulin is secreted by the liver?
IgA.
Where is free bilirubin converted into conjugated bilirubin?
Within hepatocytes.
RBCs are broken down within phagocytes where they are converted to ___, ___, and then ___.
heme; biliverdin; bilirubin.
Within the hepatocyte, bilirubin is conjugated to ___.
bilirubin diglucuronide.
What are other terms which all mean conjugated bilirubin?
(1) Water soluble bilirubin
(2) Direct bilirubin
(3) Bilirubin diglucuronide
Within the small intestine bacteria converts bilirubin to ___, then oxidized to ___.
urobilinogen; urobilins.
Once bilirubin is oxidized to urobilins, how does the body get rid of it?
Excreted into the feces or can enter circulation to be removed by the kidney (urine).
How is total bilirubin calculated?
Unconjugated + Conjugated Indirect + Direct.
What is delta bilirubin?
Covalently bound monoconjugated bilirubin + albumin.
What occurs when we have a large amount of bilirubin being produced, and the liver conjugates it all?
It can overflow into the urine because conjugated bilirubin is soluble and can be released into the circulatory system.
Reference range of bilirubin.
<1.0 mg/dL
Predicted value of bilirubin for someone with jaundice.
2 - 3 mg/dL.
Predicted value of bilirubin for someone with kernicterus (bilirubin deposits in the CNS).
15 - 20 mg/dL.
___ excess is similar to jaundice in hyperbilirubinemia.
Vitamin A.
In a patient with pre-hepatic jaundice, what is the predicted laboratory results for the following tests:
(1) Bilirubin: Total & Conjugated
(2) Fecal urobilinogen
(3) Urine urobilinogen
(1) Bilirubin: Total & Conjugated - increased
(2) Fecal urobilinogen - increased
(3) Urine urobilinogen - normal to increased
What likely condition causes an increase in unconjugated bilirubin and negative conjugated bilirubin?
Gilbert’s disease; an issue with bilirubin uptake amongst hepatocytes.
What condition would likely cause an increase to conjugated bilirubin and a decrease to unconjugated bilirubin?
Crigler-Najjar syndrome; the absence or defect to the enzyme that is responsible for the conjugation of bilirubin.
Describe hepatic regurgitation jaundice.
Conjugated bilirubin leaks out of the cells leading to conjugated bilirubin spilling into the urine.
A patient with the following symptoms: - AST and ALT >10x - Decreased albumin - Increased globulins - Increased conjugated bilirubin - Increased urine direct bilirubin What is the likely condition?
Hepatic regurgitation jaundice.
Describe post-hepatic impairment.
Conjugated bilirubin cannot reach the large intestine via bile causing a regurgitation into blood of conjugated bilirubin; excreted through the urine.
Post-hepatic conditions would cause a(n) ___ to total and conjugated urine bilirubin; ___ result for fecal and urine urobilinogen; ___ ALP value; ___ to ___ fecal color.
Increase; negative; pale; clay.
What causes newborn jaundice & kernicterus in newborns?
Immaturity of the hepatic system for uptake, conjugation and excretion of bilirubin.
Kernicterus causes the albumin binding capacity to exceed ___ mg/dL.
15-20.
Define cirrhosis.
Loss of normal microscopic architecture of the liver with resulting fibrosis (histological changes).
What are the expected lab results for a patient with cirrhosis?
- AST & ALT
- GGT
- Albumin
- AST & ALT increased
- GGT increased
- Albumin decreased
