Digestive system + nutrition (chp.4)

• Digestion


  Process that converts food into very small soluble pieces, breakdown of food
• Ingestion 


  Food goes into the mouth
• Digestion 


  Food is broken down into smaller molecules
• Absorption 


  Food molecules pass through the guy wall into the body
• Assimilation 


  Food molecules are used by cells for energy, growth etc
• Egestion 


  Unabsorbed food is ejected from the digestive system
• Mechanical digestion 


  Food is cut,chewed and churned into smaller pieces
• Chemical digestion 


  Enzymes help break the food down into smaller, simpler molecules
• Enzymes


  Catalysts that speed up or slow down the rate of chemical reactions without being used up themselves
• Structure of digestive system

  1. Mouth: food is chewed, saliva added
  2. Salivary Glands: makes saliva
  3. Oesophagus: peristalsis pushes food up and down from the stomach
  4. Stomach: HCL acid & enzymes assist to break down protein
  5. Small intestine: enzymes digest food and it is absorbed
  6. Liver: produces bile, detoxifies alcohol
  7. Gall bladder: stores bile
  8. Pancreas: produce many enzymes(releases them into small intestine)
  9. Large intestine: absorbs water, produces Vit.K
  10. Rectum: stores faeces
  11. Anus: egests faeces