1. Digest a Tennis Ball

2. Movie

3. Review From Earlier This Week
Take out your digestive system diagram and notes. Use them to answer this Entrance Ticket question!

4. Entrance Ticket
1. What is digestion? 2. How is mechanical digestion different from chemical digestion?

5. Rate Your Starting Point on the Learning Goal
4 – I can explain peristalsis and what tissues make up the digestive system. 3 – I can explain peristalsis and the role of sphincters. 2 – I can explain how food moves but not the direction it moves. 1- I’m not sure how food moves through the digestive system. 0 – I don’t know what the digestive system is.

6. TSWBAT explain how food moves through the digestive system.
Learning Goal
TSWBAT explain how food moves through the digestive system.

7. Guiding Questions
How do you think food moves through the digestive tract (tube)?
What do you think happens to food as it moves along the digestive tract?
Why do you think the digestive tract gets narrower in some places?

8. Review - Steps in Digestion
Chew the food mechanically with the teeth.
Swallow food with help from the tongue
Food travels down the Esophagus
A valve opens into the Stomach
The Stomach stores, mixes, and empties the food.

9. Steps in Digestion The food is digested in the Small Intestine
Dissolved by juices from the pancreas, liver, and intestine
Nutrients are absorbed by villi (little projections in the small intestine).
Food enters the large intestine and excess water is removed.
The waste products move into the colon

10. It’s a LONG Way to the End!
The entire digestive system is 914 cm in length or about 30 feet long!!
Food takes between 1 and 3 days to travel its entire length.
In the average human lifetime, the digestive system handles approximately 65 tons of food and drink. This is equal to the weight of 12 elephants!

11. Lab Overview
In this lab, we will move a tennis ball through a piece of plastic tubing, to model the movement of food through digestion. The tube will be marked with digestive organs and their distances.

12. How does food move through the digestive system?
Question
How does food move through the digestive system?

13. Hypothesis
If food is swallowed, then it moves through the digestive system because _______________

14. Materials Lab sheet Tennis Ball Meter Stick Long Plastic Tube
Masking Tape
*The plastic tube represents the digestive system

15. Review Lab Sheet Please do not write on your lab sheet.
Read the procedure with your group.
When you measure to mark where an organ goes, do you go from the last organ or from the beginning of the tube?

16. Procedure Person B – Get the plastic tube and tennis ball.
Person C – Get the meter stick, tape and marker.

17. Procedure – How to Mark the Tubing
Place a small piece of tape at the distance you measure. Mark on the tape the name of the organ and the distance FROM THE LAST ORGAN.

18. Procedure continued
3. Everyone – Take turns measuring organ lengths and labeling. Use the chart on your lab sheet to measure.
Everyone – Take turns moving the ball through the “digestive system”.
Discuss the organs the “food” is moving past, and what is happening at each.

19. Organ Lengths Organ Length: cm Mouth 11
Esophagus (use mouth as starting point) 25
Stomach 22
Small Intestine
690
Large Intestine
152
Rectum 14

20. Clean -Up Person D – Remove the tape pieces and throw away.
Everyone – Help fold (not roll!) the tube neatly.
Person A – Return the tennis ball, lab sheet and tube.
Person D – Return the marker, meter stick and tape.
Everyone – Answer the three BLUE questions on page 9.

21. What did we learn? How does food move through the digestive system?
What did the squeezing of your hands represent?
What do you think the digestive system is made of if it can squeeze like that?

22. Peristalsis
Peristalsis is the squeezing of muscles of the esophagus to move food down to the stomach.
It would move food toward the stomach even if you were standing on your head!

23. Sphincters
Sphincters are rings of muscles that act like valves, to let food go forward but not backward.

24. Exit Ticket
Write your name and period # at the top. Write your answer only.
What process squeezes food through the digestive system?
Why does food move only in one direction?

25. Rate Yourself on Today’s Learning Goal
4 – I can explain peristalsis and what tissues make up the digestive system. 3 – I can explain peristalsis and the role of sphincters. 2 – I can explain how food moves but not the direction it moves. 1- I’m not sure how food moves through the digestive system. 0 – I don’t know what the digestive system is.