The Digestive System

• Tissue


  A group of cells with a similar structure and function
• Organ


  A group of tissues working together for a specific function
• Organ system


  Organs grouped together to form organisms
• Main nutrients in food


  • Carbohydrates
  • Protein
  • Lipids (fats)
• Digestion


  1. Large food molecules broken down into small molecules by enzymes

  2. Small molecules absorbed into bloodstream
• Digestive system


  • Food chewed in mouth, enzymes in saliva begin digestion
  • Food passes down esophagus into stomach, enzymes and hydrochloric acid digest proteins
  • Food passes into small intestine, pancreas releases enzymes to digest starch, protein and lipids, liver releases bile to aid lipid digestion
  • Small food molecules absorbed into bloodstream in small intestine
  • Fluid passes through large intestine, water absorbed, feces released
• Products of digestion


  Used by body to build new carbohydrates, lipids and proteins, some glucose used in respiration