1. The Upper Digestive System
By Ms. Johnson
The Upper Digestive System

2. Two types of digestion…

3. Mechanical vs. Chemical Digestion
Mechanical digestion is a physical process. The food is getting broken into smaller pieces.
Can you think of a place where this happens?
Chemical digestion is a process where the food is chemically broken into its most basic parts.
Where do you think that this might happen?

4. Mechanical Digestion
Mechanical digestion = physically breaking apart the food.

5. Chemical Digestion
Chemical Digestion = enzymes (chemicals) break down the food into its parts.

6. Let’s begin. You may now eat your candy and start on the amazing digestive journey!

7. The Mouth
The teeth mechanically digest the food by breaking it up into small pieces.
Your saliva (spit) has enzymes that begin to chemically digest the food while in your mouth.

8. The Esophagus
The esophagus is the tube that goes from your mouth to your stomach.
Food moves when the muscles of the esophagus contract causing the food to be moved down.
This is called peristalsis.

9. Esophagus

10. The Stomach The stomach is where food goes after you swallow it.
Both mechanical and chemical digestion occur in the stomach.
The stomach churns to mix the food with the acid. This is mechanical digestion.
The stomach then chemically digests the food with a couple of chemicals.
Pepsin breaks down protein.
Hydrochloric Acid kills all bacteria and allows for the food pepsin to work well.

11. The Stomach