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Bile

~500mls bile secreted per day in the liver
Secreted into liver canaliculi by hepatocytes
Release stimulated by CCK, gastrin, secretin

Function

  1. Emulsification of fat (ADEK vitamins)
  2. Aids in absorption

 

Composition of bile

  1. Water - 97%
  2. Bile Salts - 0.7% - Cholic/Chenodeoxycholic acid
  3. Bile Pigments - 0.2%: bilirubin/biliverdin
  4. Other 2%: Fatty acids, cholesterol, lecithin

Bilirubin / Jaundice

Normal Metabolism Jaundice Classification
  1. Broken down Hb in reticuloendothelial system
  2. Reaches liver bound to albumin
  3. Taken up into liver via transporter
  4. Conjugated to bilirubin-Digluconuride
  5. CBili enters bile and into gut and out into poo
  6. Small amount enters circulation and reaches urine / small amount in gut converted to urobilinogen and out into urine

Pre-hepatic

  • Haemolytic anaemia
  • Increased cell turnover - cancer/lymphoma

Hepatocellular

  • Failure of uptake: Gilbert's
  • Failure of conjugation: Crigler-Najjar
  • Infections - CMV, Hepatitis
  • Autoimmune

Post-hepatic

  • Cholestasis / obstruction / biliary atresia

Investigations in jaundice

  1. FBC
  2. Reticulocyte count
  3. Clotting
  4. LFTS
  5. Virology
  6. Autoantibody

 

 

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