Steps of Digestion

  • First you chew the food in your mouth which breaks it down and the salivary glands release amylase to digest starch
  • Food passes down oesophagus into the stomach
  • In the stomach enzymes begin the digestion of proteins. The stomach also contains HCl which helps the enzymes digest the proteins. The food spends several hours in the stomach. The churning action of the stomach muscles turns the food into a fluid increasing surface area for enzymes
  • The fluid passes into the small intestine and chemicals are released into the small intestine from the liver and pancreas.
  • The pancreas releases enzymes that continue the digestion of starch and protein, they also start the digestion of lipids.
  • The liver releases bile which helps speed up digestion of lipids and also neutralises stomach acid
  • The walls of the small intestine release enzymes to continue the digestion of protein and lipids
  • In the small intestine the small food molecules produced by digestion are absorbed into the blood stream by active transport or diffusion
  • Now the fluid makes its way through the large intestine where water is absorbed into the bloodstream
  • Then waste products are released from the body

The products of digestion are then used by the body to build new carbohydrates, lipids and proteins Some glucose produced is used in respiration