1. The Digestive System
From Food to Nutrients

2. The Digestive System - Definition
The function of the digestive system is to break down food into nutrients and absorb them into the blood stream where they can be delivered to all cells of the body to use in cellular respiration.

3. From Food to Nutrients – Pizza!

4. The Mouth Teeth break food into smaller pieces
Saliva is secreted into the mouth from the salivary glands to help lubricate the food
Mouth forms a bolus (ball) of food that can be swallowed easily

5. The Pharynx – Don’t Choke!
Part of both digestive and respiratory system
When swallowing, a small flap called the epiglottis blocks the opening of your windpipe
Allows food to go down the esophagus
“Down the wrong tube”

6. The Esophagus 10 inches long, stretchy pipe
Transports food from mouth to stomach
Food doesn’t just slide down, muscles contract to push the food
down – peristalsis
2-3 seconds to go down

7. The Stomach Stretchy, J-shaped sac
Stomach is like a mixer – slowly mashing together the food, breaking it into smaller pieces (stomach muscles)
Gastric juices help break the food down

8. The Small Intestine – Not So Small!
1½ - 2 inches thick, 22 ft long (stretched out)
Food spends about 4 hours in the S.I.
3 organs secrete liquid into the beginning of the S.I. to help break down food even more:
Pancreas
Liver
Gallbladder

9. The Pancreas
Secretes juices into the small intestine to help break down fats and proteins

10. The Liver and the Gallbladder
Liver produces digestive juice called bile
Gallbladder stores bile from liver until needed
Bile secreted into the small intestine to helps absorb fats

11. Absorption
As food travels through the small intestine, it is broken down more and more into elements that can be used by the body
Nutrients are absorbed into the blood stream to make their way to your cells

12. The Large Intestine 3-4 inches thick, 5 ft long
After the nutrients get absorbed in your S.I., there’s stuff left over that your body can’t digest - waste
L.I. absorbs water as waste passes through (solidifying)
Very little digestion occurs

13. The Appendix Tiny tube with closed end coming off the L.I.
Has no function!

14. The Last Stop Last part of the large intestine is the rectum
Solidified
Storage for waste until it is released from our bodies through the anus

15. Very Important!
The digestive system is very important because without it, your body couldn’t get the nutrients it needs in order to grow big and strong!