The functions of the gut

• what are the 4 main functions that the human gut performs?

  • ingestion
  • digestion
  • absorption
  • egestion
• what is ingestion?

  taking food into the body through he buccal cavity (mouth)
• what is digestion?

  the breakdown of large insoluble molecules into soluble molecules that are small enough to be absorbed into the blood
• what are the 2 types of digestion?

  • mechanical digestion
  • chemical digestion
• what is mechanical digestion?

  cutting and crushing by teeth and muscle contractions of the gut wall increase the surface area over which enzymes can act
• what is chemical digestion?

  digestive enzymes, bile and stomach acid contribute to the breakdown of food
• what is absorption?

  the passage of molecules and ions through the gut wall into the blood (capillaries or lacteals)
• what is egestion?

  the elimination of undigested waste not made by the body, including food that can’t be digested (e.g. cellulose)
• what is this an image of?

  the steps of the gut

  
• what is this an image of?

  the simplified structure of the gut

  
• whats the function of the mouth?

  ingestion and digestion of starch and glycogen
• what is the function of the oesophagus?

  the carriage of food to the stomach
• whats the function of the stomach?

  digestion of protein
• whats the function of the duodenum?

  digestion of carbohydrates, fats and proteins
• whats the function of the ileum?

  digestion of carbohydrates, fats and proteins and absorption of digested food and water
• whats the function of the colon?

  absorption of water
• whats the function of the rectum?

  storage of feces
• whats the function of the anus?

  egestion
• what is this an image of?

  the structure of the human gut along with its associated organs