Digestion

• Absorption of food


  Small intestine
• Absorption of water


  Large intestine
• Digestion of food


  1. Mouth

  2. Stomach

  3. Small intestine
• Mouth


  • Structure: Teeth and tongue
  • Function: Mechanical digestion of food, grinds food up, moistens food so it is easily swallowed
• Salivary gland


  • Glands with ducts, found in the mouth
  • Produces saliva which contains amylase to digest starch into glucose
• Stomach


  • Muscular bag which produces hydrochloric (HCL) acid
  • Churns food into liquid called chyme, contains proteases, walls produce mucus, has a pH of 2 to digest food
• Mucus stops the stomach from being digested by hydrochloric acid
• Liver


  • Large organ, which is also a gland
  • Produces bile to emulsify fats
• Pancreas


  • An elongated gland which contains specialised groups of cells called islets of Langerhans
  • Secretes pancreatic juice which contains enzymes such as amylase, lipase and protease to further digest food
• Small intestine


  • Long muscular tube, lining covered by villi and micro villi
  • Further digestion of food, absorption of food into the blood. Nutrients absorbed here include glucose, amino acids and fatty acids
• Large intestine & colon

  • Long muscular tube, about 1.5m long
  • Digests food using enzymes such as amylase and protease, water reabsorbed
• Rectum & anus


  • Final section of large intestine
  • Undigested food compacted and stored in rectum before being egested through anus