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 Ticket1. 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 Questions1. 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 Digestion1. Chew the food mechanically with the

teeth.2. Swallow food with help from the tongue3. Food travels down the Esophagus 4. A valve opens into the Stomach5. The Stomach stores, mixes, and

empties the food.

Steps in Digestion5. The food is digested in the Small

Intestinea) Dissolved by juices from the pancreas, liver,

and intestine6. 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 OverviewIn 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 _______________

Materials1. Lab sheet2. Tennis Ball 3. Meter Stick4. Long Plastic Tube5. Masking Tape

*The plastic tube represents the digestive system

Review Lab Sheet1. 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?

Procedure1. 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 LengthsOrgan 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 TicketWrite 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.