Liver

• functions

  • regulation of blood glucose
  • production and regulation of lipids
  • synthesis of plasma proteins
  • transamination to produce non-essential amino acids
  • deamination
  • detoxification
• what is transamination


  • process of converting amino acids from diet to essential amino acids that cannot be obtained by diet
• what is deamination


  excess amino acids are removed by the liver

  • amine group removed from molecule, combines with carbon dioxide to form urea, which is excreted by the kidney
  • rest of the molecule can be used in respiration
• location of liver


  upper right of abdominal cavity, just below the diaphragm
• structure of liver


  • made up of several lobes
  • several connections

  bile duct

  hepatic artery

  hepatic vein

  hepatic portal vein
• hepatic vein function


  returns blood back to general circulation

  composition of the blood is regulated with excesses reduced and shortages replaced
• hepatic artery function


  brings high pressure oxygenated blood to liver, rich in oxygen and low in waste
• hepatic portal vein function

  brings low pressure blood from intestine to liver, rich in dissolved nutrients, low in oxygen and high in carbon dioxide
• bile duct function

  • moves bile to gallbladder for storage
  • or moves into small intestine where it neutralises stomach acid and emulsifies lipids
• what are lobules


  • cylindrical structures
  • at the centre is hepatic vein
  • hepatic artery and vein are at opposite sides
• sinusoids


  blood-filled channels, flow towards the central vein
• sinusoids lined with hepatocytes, which regulate the composition of blood
• bile canaliculi

  • blind ending channels
  • lined by hepatocytes, secrete bile into channel
  • flows away from centre of lobule to branch of duct at the periphery
• Kupffer cells


  • phagocytic
  • capture and engulf any bacteria that enter from intestines
  • also destroy old erythrocytes
• carbohydrate metabolism


  • insulin allows conversion of glucose to glycogen
  • glucagon causes depolymerisation of glycogen to glucose
• what is detoxification


  the break down of toxic products in the body
• how does detoxification occur


  hepatocytes contain catalase and alcohol dehydrogenase
• how does catalase detoxify hydrogen peroxide


  spilts the molecule into oxygen and water
• how does alcohol dehydrogenase detoxify alcohol


  breaks ethanol down into ethanal, which is then converted into ethanoate which can be used to build up fatty acids or used in respiration
• what is cirrhosis


  a disease where normal liver tissue is replaced by fibrous scar tissue

  • multiple causes like genetics and hepatitis C
  • most common cause is excessive alcohol drinking