Digestive system

1. Digestive system

2. Digestive system • ?. mouth • A. oesophagus • B. stomach • G. small intestine • ?. Duodenum • ?. digestion – bile • - enzymes • D. large intestine • ?. the anus • E. Liver • F. Gall Bladder • C. Pancreas

3. What do these words mean? • Ingestion • Digestion • Absorption • Assimilation • Egestion

4. Digestion • 2 types – mechanical and chemical digestion. • Digestion is speeded up by enzymes (biological catalysts). • Muscles are also responsible for moving food along the gut (circular and longitudinal muscle layers). • Waves of muscle contraction help push the food along the gut – peristalsis.

5. Digestion Duodenum • The mouth, stomach and first part of the small intestine make up the duodenum. • They all break down the food using enzymes. Ileum • Digestion continues in the last part of the small intestine (ileum). • This is where the digested food is absorbed.

6. Digestion • The last part of the gut, the large intestine is mainly concerned with absorbing water out of the remains and storing waste products (faeces) before they leave the body.

7. Ingestion • Taking food into the body (very start of the digestive system).

8. Digestion • Large insoluble molecules are broken down into small soluble molecules. • Starch digestion begins. • Protein digestion begins. • All types of digestion occur.

9. Absorption • The transfer of digested substances from the intestine into the blood. • Majority of absorption. • Water absorption

10. Assimilation • The soluble products of digestion are taken to cells and used to make structures in the cells. • E.g. glucose converted to glycogen • Amino acids built up into proteins • Fatty acids and glycerol turned into lipid for storage.

11. Egestion • Removable of waste material that could not be digested.