digestive system

• What is the role of the salivary glands?


  - Teeth break down food

  - Salivia is produced - makes swollowing easier

  - produces amylase
• What is the purpose of the stomach?

  - Muscular walls - mechanically mixes food around

  - Produces protease (optimum PH) and hydrochloric acid
• What is the purpose of the large intestine?


  - Absorbs water and salts
• What is the purpose of the small intestine?


  - Absorbs smaller digested molecules into bloodstream
• How are small intestines adapted?

  - Villi

  ->increase SA for more absorption

  -> blood capillaries provide rich blood supply to maintain concentration gradient for AT and diffusion

  • villi are only one cell thick - for short diffusion distance
  • many mitochondria to release energy needed for at
• What is the function of the liver?


  - Produces bile
• What is the function of bile?


  emulsifies fats - easier to absorb
• Where is bile stored?


  Gallbladder
• What is the purpose of the pancreas?


  - Produces carbohydrase, protease, lipase and releases them into the SI
• what does bile do?

  • it is an alkalin eso it can neutralise hydrochloric acid in the stomach
  • it emulsifies fat from large droplets into smaller ones which increases SA
• why does the bile increase SA and alkaline PH help

  • so the lipase can chemically break down lipids into fatty acids and glycerol at a faster rate }
• what are the products of digestion?

  • used to build new carbs, lipids and proteins which are required for cells to function and grow
  • some glucose is used for respiration
  • amino acids are used to build new proteins such as enzymes
  • products of lipids can be used to build cell membranes and hormones