Organisation

• Digestive system

  1. Mouth

  2. Salivary glands, Oesophagus

  3. Stomach

  4. Pancreas

  5. Liver

  6. Gall bladder

  7. Small intestine

  8. Large intestine

  9. Rectum

  10. Anus
• Small intestine


  • Thick smooth muscle layer
  • Thin muscle layer and epithelium
  • Intestinal lumen
  • Intestinal villi
• Intestinal villi


  Increase surface area for absorption of soluble nutrients
• Digestive enzymes


  • Amylase
  • Protease
  • Lipase
• Amylase


  Breaks down starch
• Protease


  Breaks down protein
• Lipase


  Breaks down lipids (fats)
• If enzymes get too cold

  They work more slowly
• If enzymes get too hot


  They will denature
• Heart


  • Blood being pumped to the lungs from the right side at the same time as blood being pumped to the body from the left side
• Blood components


  • Red blood cells
  • White blood cells
  • Platelets
  • Plasma
• Red blood cells


  Carry oxygen
• White blood cells


  Kill pathogens
• Platelets


  Clot blood
• Plasma


  Liquid that carries blood cells, hormones, nutrients and CO2
• Types of blood vessels

  • Capillary
  • Artery
  • Vein
• Capillary


  • Small, low pressure, short diffusion distance
• Artery


  • Thick walls, small lumen, high pressure
• Vein


  • Thin walls, large lumen, low pressure, valves
• Transpiration


  Evaporation of water from leaves
• Food tests


  • Protein (biuret test)
  • Lipids (ethanol test)
  • Starch (iodine test)
  • Sugars (Benedict's test)
• Biuret test

  Positive result is purple
• Ethanol test


  Positive result is cloudy white
• Iodine test

  Positive result is black
• Benedict's test


  Positive result is brick red