The Human Digestive System

The Human Digestive System

1. Oesophagus

   • Is a long muscular tube that starts at the mouth and ends at the stomach
   • Peristalsis
     • Is the process of pushing food through the digestive track

2. Mechanical digestion

   • Food sliced,torn and crushed
   • Physical change because no new substance added

3. Chemical digestion

   • Large complex substances are broken down
     • Food broken down into simpler chemicals by saliva
   • Saliva
     • Watery liquid containing a chemical that begins the digestion of starch

4. Stomach

   • Food stored
     • Muscle walls contract and relax
       • Mixed with gastric juice
         • Containing Hydrochloric acid,mucus,digestive juices

5. Mouth/teeth

   • Start of digestive system
     • Teeth
       • Premolar,molar,incisor,canine

6. Small intestine

   • Longest section of the digestion track
     • Diameter is 3 cm
   • Duodenum
     • First part of the small intestine
       • Two tubes entering the duodenum carry chemicals
         • Important digestion from the pancreas and liver

7. Large intestine

   • Final section of the digestion track
   • 1.5 meters long
     • 6-7cm in diameter
       • Water and nutrients absorbed into the body from the food

8. Liver

   • Largest internal organ
     • Performs over 500 chemical processes

9. Pancreas

   • Produce pancreatic juice
     • Containing chemicals that help digest fat,protein and carbohydrates

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