1. THE HUMAN BODY The Digestive System
Mr. Parr Digestion Song

2. Digestion 1. Its Purpose…..
a process where food is broken down into substances that can be used by the cells of the body.

3. 3. The Digestive Tract
The digestive tract is a series of hollow organs that creates a long tube. There are 5 major stops along the way for digesting food.
Mouth
Esophagus
Stomach
Small Intestines
Large Intestines

4. 2. TYPES OF DIGESTION CHEMICAL MECHANICAL
Occurs when food is broken down into smaller pieces.
Occurs when food is chemically changed into simpler substances that can be used by the body.

5. 4. Digestion begins when…..
Food enters the mouth. The teeth chop and grind food into smaller pieces. The tongue helps push food to the back of the mouth where it is swallowed.
What type of digestion is this?

6. 5. In the mouth Salivary Glands release saliva to soften the food and begin the process of chemical digestion.
6. Saliva contains enzymes which break down the food into a useable form.

7. Did you know?
If saliva cannot dissolve something, you cannot taste it.
In order for foods, or anything else, to have a taste, chemicals from the substance must be dissolved by saliva. If you don’t believe it, try drying off your tongue before tasting something.
On average, you produce 1.8 quarts of saliva each day.
During your lifetime, you will produce enough saliva to fill two swimming pools.

8. 7. The ball of food produced is a bolus.
8. After being swallowed, the food passes into the esophagus a muscular tube which connects the mouth to the stomach.
9. The epiglottis prevents food from entering the trachea, also known as the Windpipe.

9. 11. Both mechanical & chemical digestion takes place in the stomach.
Chemical digestion- Gastric Juices like Hydrochloric acid break food particles into smaller molecules
Mechanical digestion- the churning of the smooth muscles physically breaks food into smaller pieces
12. Both chemical and mechanical digestion produces chyme , which is the soupy liquid in stomach
10. Peristalsis is the squeezing motion that pushes food down the digestive tract.

10. Did you know?
A meal may take up to three days to pass through your digestive system. It spends about three hours in your stomach.
We eat about 1,100 pounds of food each year.

11. Did you know?
The acid in your stomach is strong enough to dissolve razorblades.
Hydrochloric acid, the type found in your stomach, is not only good at dissolving the pizza you had for dinner but can also eat through many types of metal.
….which is WHY….
You get a new stomach lining every three to four days. The mucus-like cells lining the walls of the stomach would soon dissolve due to the strong digestive acids in your stomach if they weren’t constantly replaced. Those with ulcers know how painful it can be when stomach acid takes its toll on the lining of your stomach.
….what process does your body use to replace the cells lining the stomach….?

12. 13. The pyloric valve connects the stomach to the small intestine, which is a very long coiled tube-like organ.

13. 14. The Liver produces bile and it is added in the small intestine to help break down food.
15. The Gallbladder stores bile produced by the liver.
16. The Pancreas
Create and release enzymatic juices into the small intestine
Produces hormone insulin to control blood sugar. Insulin is released into bloodstream.

14. Small Intestines
17. Digestion is completed In the small Intestines is where the absorption of nutrients takes place.

15. 18. Villi are small finger-like projections that absorb the nutrients from the small intestine and carries them in the bloodstream to all the cells of the body.

16. Did you know? The largest internal organ is the small intestine.
Despite being called the smaller of the two intestines, your small intestine is actually four times as long as the average adult is tall.
If it weren’t looped back and forth upon itself it wouldn’t fit inside the abdominal cavity.

17. The Appendix
19. The pouch-like appendix is located between the large and small intestines. It is believed that this organ is a storage place for good bacteria used by the large intestines

18. Large Intestine
20. Materials that are not digested move into the large intestine.
21. Water is taken out of the remaining waste creating a solid called feces.
22. Feces are stored in the rectum until it leaves the body through an opening called the anus.

19. Did you know?
Every day 3 gallons of digested food, liquids and digestive juices flow through the digestive system, but only 3 ounces are lost in feces.
The average person produces about 1 ounce of stool for every 12 pounds of body weight.
A cow has three stomachs. It chews its food once and lets it digest partially in one stomach. Then it regurgitates the food up and chews it again continuing the cycle two or more times until its cud is fully digested.

20. Exit Slip What is the purpose of the digestive system?
Where does the process of digestion begin?