1. 30.3 The Digestive System Functions of the Digestive System
The Process of Digestion
Absorption and Elimination

2. Functions of the Digestive System
Ingestion
Digestion
Absorption
Elimination

3. Ingestion
This is simply the act of putting food into your mouth

4. Digestion Starts in the mouth and continues through to the stomach
Two types:
Chemical Digestion
Mechanical Digestion

5. Chemical vs. Mechanical Digestion
Enzymes break down food
Examples: Amylase (mouth and small intestine)
Mechanical:
The physical breakdown of large pieces of food into smaller pieces.
Examples: chewing, stomach churning

6. Absorption
Food is broken down by digestion into small molecules that can be absorbed in the small intestine.

7. Where else does absorption take place?
Water is absorbed from the undigested material in the large intestine.

8. Elimination
Indigestible material is passed through the system and out of the body (feces).

9. Digestion Flow Chart Ingestion: Mouth Then…
Digestion: Mouth, stomach, small intestine
Absorption: Small and large intestine
Elimination: Large intestine

10. Enzymes
Enzymes are a type of protein that are involved in chemical digestion.
Enzymes break large food molecules into smaller molecules.

11. Enzyme Example

13. Enzymes: What and Where
In the mouth salivary amylase breaks starches down into sugars; disaccharides.

14. Enzymes: What and Where.
In the stomach, Pepsin starts the process of breaking proteins down.

15. Enzymes: What and Where.
In the small intestine, three enzymes produced by the pancreas contine the process of breaking down food.

16. Enzymes: What and Where.
Pancreatic Amylase: continues the breakdown of starches into sugars. (monosaccharides)

17. Enzymes: What and Where.
Tyrpsin, in the small intestine, continues the breakdown of proteins into amino acids.

18. Enzymes: What and Where.
Also in the Small Intestine, Lipase breaks down fat (lipids) into fatty acids.

19. Enzymes: What and Where
The pancreas also produces sodium bicarbonate that neutralizes the stomach acid in chyme.

20. Enzymes: What and Where
The small intestine produces its own enzymes (Matase, Sucrase, and Lactase, that continue the breakdown of sugars into monosaccharides.

21. Enzymes: What and Where
In the small intestine, Protease, continues to break down proteins into amino acids

22. Enzymes: What and Where
Another important digestive fluid is called bile.
Bile is produced by the liver, and separates fats so lipase can break it down.

23. Absorption
In the small intestine the villi increase the surface area of the inner layer and that is used to absorb nutrients into the bloodstream.
Fatty acids, monosaccharides, and amino acids

24. Absorption and Elimination
The Large intestine:
Absorbs water
Eliminates indigestible material from the body.

25. Coloring your Digestive system
Color all the organs that food actually passes through a shade of “RED”
Color all the organs that are involved in digestion but that food does not pass through a shade of “Blue”
Write next to each letter what stage in digestion those organs take place.
Now label where the different enzymes interact with food in the digestive system, and what they are breaking down.