Digestive system

Digestive system

1. 1) Mouth

   • Food is moistened with saliva from the salivary gland.
     • The salivary glands produce amylase enzyme in the saliva, which breaks down starch.
       • Food is chewed to form a ball (bolus) before being swallowed.

2. 2) Oesophagus

   • This tube takes food from the mouth to the stomach.
     • Its lined with muscles that contract to help the bolus move along, by peristalsis (Muscles contract in waves to squeeze food down towards the stomach)

3. 3) Stomach

   • It pummels the food with its muscular walls.
     • It produces the protease enzyme, pepsin.
       • It produces hydrochloric acid for 2 reasons: To kill bacteria and to give the right pH for the protease enzyme to work (pH 2 -acidic).

4. 4) Small intestine

   • Produces protease, amylase and lipase enzymes to complete digestion.
     • This is also where 'food' is absorbed out of the digestive system into the body.

5. 5) Large intestine

   • Excess water is absorbed from the food. Leaving waste material behind.

6. 6) Pacreas

   • Produces protease, amylase and lipase enzymes. It releases these into the small intestine.

7. 7) Liver

   • Also where bile is produced. Bile neutralises stomach acid and emulsifies (digest) fats.
     • Absorbed nutrient are transported here and are processed.

8. 8) Gull bladder

   • Where bile is stored, before it's released into the small intestine.