1. Digestive System

4. Us!

5. Digestive System overview:

6. Functions of the digestive system
Ingestion
Mechanical processing
Digestion
Secretion
Absorption
Excretion

7. The Digestive process can be broken down into 4 parts:
Ingestion – taking in of nutrients
Digestion – breakdown of complex molecules into smaller components by enzymes
Absorption- transport of digested nutrients to the tissue of the body
Egestion – removal of waste food material from the body

8. Ingestion: eating
Physical digestion begins in the mouth, where food is chewed and formed into a bolus (greek word for ball) by the tongue.

9. In the mouth: physical and chemical digestion starts!
Teeth: physical breakdown of food into smaller pieces.
Saliva: chemical breakdown of starch, lubricates food so it can be swallowed and makes food taste…good or bad

10. Teeth…a comparison

11. Food for thought…….dental implants…

12. Saliva:
Contains the enzyme AMYLASE that breaks down starch into simple sugars
Lubricates food
Dissolves food particles
Activates the taste buds (Scientific American March 2001)

14. Test your tastebuds This is what you need to do:
Conduct a simple scientific experiment to find out whether you have a supertaster tongue or not. All you need is:
Food colouring
Cotton buds
Reinforcement rings for hole-punched paper
Magnifying glass
This is what you need to do:
Using a cotton bud, swab some food colouring on to the tip of your tongue
Place a reinforcement ring on your tongue
Count the pink dots within the reinforcement ring. This may be easier with a magnifying glass
The pink dots are your fungiform papillae. They don't take up the food colouring. These papillae are the tiny bumps on your tongue that house your taste buds. The more papillae you have, the more taste buds you have and the more sensitive to taste you are. On average, non-tasters have fewer than 15 papillae in that area, while supertasters have over 30.