Digestive System

• Stomach


  Main organ where food is digested
• Small intestine


  Main organ where food is digested and soluble food molecules are absorbed into the blood
• Digestion


  Enzymes break down large insoluble food molecules into smaller, soluble ones
• Small intestine


  • Has a very large surface area as it is covered in villi
  • Has a good blood supply
  • Has short diffusion distances to the blood vessels
  • This greatly increases diffusion and active transport from the small intestine to the blood
• Undigested food


  Squeezed onwards into the large intestine
• Large intestine


  Where water is absorbed from the undigested food into the blood
• Faeces


  Material left after water absorption, stored and then passed out of the body through the rectum and anus
• Liver


  Produces bile which helps in the digestion of lipids
• Organ


  A single part of the body that performs a specific function
• Organ system


  Groups of organs that perform specific functions in the body
• Organs in an organ system rely on each other to function properly
• Digestive system


  • Exchanges substances with the environment
  • Breaks down large insoluble molecules into smaller, soluble molecules that can be absorbed and used by cells
• Digestive system


  • Muscular tube that squeezes food through it
  • Starts at mouth and finishes at anus
  • Contains many different organs including glands like pancreas and salivary glands that make and release digestive juices containing enzymes to break down food
• Digestion


  Takes place in the digestive system
• Main organs of the human digestive system

  • Mouth (containing teeth, tongue and salivary glands)
  • Oesophagus
  • Stomach
  • Liver
  • Gall bladder
  • Duodenum
  • Bile duct
  • Small intestine
  • Pancreas
  • Appendix
  • Large intestine
  • Rectum
  • Anus
  • Diaphragm
• The pancreas and salivary glands make and release digestive juices containing enzymes to break down food