Digest a Tennis Ball
Movie
Review From Earlier This Week
Take out your digestive
system diagram and notes.
Use them to answer this
Entrance Ticket question!
Entrance Ticket
1. What is digestion?
2. How is mechanical digestion
different from chemical
digestion?
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.
Learning Goal
TSWBAT explain how
food moves through the
digestive system.
Guiding Questions
1. How do you think food moves through the
digestive tract (tube)?
2. What do you think happens to food as it
moves along the digestive tract?
3. Why do you think the digestive tract gets
narrower in some places?
Review - Steps in Digestion
1. Chew the food mechanically with the teeth.
2. Swallow food with help from the tongue
3. Food travels down the Esophagus
4. A valve opens into the Stomach
5. The Stomach stores, mixes, and empties the
food.
Steps in Digestion
5. The food is digested in the Small Intestine
a) Dissolved by juices from the pancreas, liver,
and intestine
6. Nutrients are absorbed by villi (little
projections in the small intestine).
7. Food enters the large intestine and excess
water is removed.
8. The waste products move into the colon
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!
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.
Question
How does food move
through the digestive
system?
Hypothesis
If food is swallowed, then it
moves through the digestive
system because
_______________
Materials
1.
2.
3.
4.
5.
Lab sheet
Tennis Ball
Meter Stick
Long Plastic Tube
Masking Tape
*The plastic tube represents the digestive
system
Review Lab Sheet
1. Please do not write on your lab
sheet.
2. Read the procedure with your
group.
3. When you measure to mark where an
organ goes, do you go from the last
organ or from the beginning of the
tube?
Procedure
1. Person B – Get the plastic tube and
tennis ball.
2. Person C – Get the meter stick, tape
and marker.
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.
Procedure continued
3. Everyone – Take turns measuring
organ lengths and labeling. Use the
chart on your lab sheet to measure.
4. Everyone – Take turns moving the ball
through the “digestive system”.
5. Discuss the organs the “food” is
moving past, and what is happening at
each.
Organ Lengths
Organ
Length: cm
Mouth
11
Esophagus (use mouth as starting point)
25
Stomach
22
Small Intestine
690
Large Intestine
152
Rectum
14
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.
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?
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!
Sphincters
• Sphincters are rings of muscles
that act like valves, to let food go
forward but not backward.
Exit Ticket
Write your name and period # at the
top. Write your answer only.
1. What process squeezes food
through the digestive system?
2. Why does food move only in one
direction?
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.