Liver and Biliary System Flashcards
What structures does the portal triad encapsulate? PBH
Portal Vein
Bile Duct
Hepatic Artery
What are the functions of the liver? (6)
Metabolism
Bile Production
Cholesterol Metabolism
Glucose storage
Iron Storage
Production of clotting factors, serum proteins, fat soluble vitamins, and proteins
What is the goal of the liver when it encounters drugs?
Elimination of foreign substances
What is the difference between phase 1 and phase 2 metabolism?
Phase 1 is the activation, while phase II is the conjugation, goal is to go from lipophilic to water solube
What is the function of Bile?
Digestion of fats in the duedenum,
What is Bile composed of? (3)
Acids, salts, phospholipids/surfactants (main ones)
How much bile does the liver excrete every day?
500-1000ml
What is the function of the gallbladder?
Used as a storage site for bile in the event the stomach needs more
What are the steps to normal Bilirubin metabolism (9)
- Hemoglobin release and breakdown (spleen, bone marrow)
- Heme enzymatically converted to bilirubin.
- Bilirubin enters the liver through the circulation
- Hepatocytes add additional functional groups to bilirubin to increase its solubility and excretion
- Most of the conjugated bilirubin is then excreted in the bile.
- Bile enters the GI tract
- A small fraction of the bilirubin is
reabsorbed and sent back to the liver - Most of the bilirubin (~90%) is excreted in
the feces after being enzymatically
reduced by colon bacteria. - The break down products contribute to
fecal colour.
Blood –> Heme –> Bilirubin –> Bile –> GI Tract –> limited reabsorption if bilirubin –> Bile is excreeted
What are the risk factors for liver disease?
Obesity/Diabetes
Exposure to chemcials/toxins
Alcohol abuse
Family history
Hep B/C
What are the symptoms of liver disease
Nausea, vomiting or loss of appetite
Abdominal swelling (ascites) or tenderness in the area of the liver
Chronic fatigue
Itchy skin (pruritus) *Dark coloured urine *Pale stool
Dementia-like confusion (if hepatic encephalopathy is present)
Ascites
How does Jaundice occur?
This is due to the livers inability to transform unconjugated bilirubin to the conjugated form, This free bilirubin escapes to the blood causing yellow colour.
What is Cirrhosis?
liver becomes fibrotic after some severe chronic injury, such that the liver becomes nodular with regenerating hepatocytes surrounded by scar tissue
What is NAFLD
Non-alcoholic fatty liver disease, which is associated with hypertension, diabetes, dyslipidemia,
Is NAFLD reversible? How?
Yes, weight loss and exercise
What is the main cause of posthepatic Jaundice Obstruction?
Intrahepatic cholestasis (bile not moving out of the liver through the ducts)
Extrahepatic obstruction of the biliary tract, which prevents bilirubin from moving into the intestines.
What is Intrahepatic cholestasis
bile not moving out of the liver through the ducts
What can Intrahepatic cholestasis caused by?
functional impairment of the hepatocytes in the secretion of bile and/or due to an obstruction at any level of the excretory pathway of bile.
What can Cholestatic jaundice be classified into?
Intrahepatic or extrahepatic cholestasis
What does cholestasis lead to?
Retention of the constituents of bile in the blood
Hepatocellular Causes (With respect to intrahepatic cholestasis)
Viral hepatitis, acute alcoholic hepatitis, parenteral nutrition
Canalicular Membrane Changes (With respect to intrahepatic cholestasis)
Drugs:oral contraceptives, antibiotics, antithyroid drugs, sulphonamides; cholestasis in pregnancy
Canalicular/Ductular Luminal Obstruction: (With respect to intrahepatic cholestasis)
Cholestasis due to sickle cell disease, bacterial infections, sepsis, cystic fibrosis
Ductopenia (With respect to intrahepatic cholestasis)
Familial, drug- induced, chronic allograft rejection, Hodgkin disease, sarcoidosis, primary sclerosing cholangitis, primary biliary cholangitis
