Transport of Absorbed Nutrients

• Glucose, amino acids, vitamins, mineral salts and water are absorbed through the blood capillaries in the villi
• The capillaries join to form larger veins that eventually open into the hepatic portal vein
• The hepatic portal vein transports the absorbed nutrients to the liver
• In the liver

  • most of the glucose is converted into glycogen and stored
  • excess amino acids undergo deanimation to form urea and glucose
• The urea is transported to the kidneys where it is excreted is a part of urine
• The remaining glucose and amino acids leave the liver via the hepatic veins and are transported in the inferior vena cava to the heart and to the rest of the body
• A large proportion of glucose is transported to the tissues (especially muscle tissues) where it is broken down by cellular respiration to CO2 and water with the release of energy
• Fatty acids and glycerol are absorbed by the lacteals of the villi
• The lacteals unite and form larger lymphatic vessels that eventually open into the thoracic duct
• Fatty acids and glycerol in the thoracic duct enter the blood system at the left subclavian vein and are transported to the rest of the body via the heart