Transport of nutrients - circulation

• Digested food molecules such as glucose, amino acids, minerals and some vitamins are soluble in water and can be transported by the circulation system.
• The molecules are absorbed by the blood capillaries in the villi and taken directly to the liver in the hepatic portal vein.
• The liver is a sorting area, storing some molecules, changing others and allowing some to continue on in the circulation system.
• Food molecules from the liver travel in veins to the heart, from where the blood is pumped into the lungs to be oxygenated. The blood returns to the heart and is pumped through arteries to all areas of the body where cells are supplied with nutrients and oxygen.
• Insoluble digested food molecules, fatty acids/some vitamins, are absorbed into the lacteals inside the villi and are transported to the thoracic duct of the lymph system. The thoracic duct returns the food molecules and fluid to the circulation system just above the vena cava which leads to the heart.