1. The
Digestive
System
What body system has the function of breaking down food for absorption  into the blood?

2. What are some ways a cracker can be broken down by the body in order for its nutrition to be absorbed into the body?
Brainstorm ideas on sheet of notebook paper.

3. Cracker Lab Cracker Lab 1/4 after 30 seconds: 1/2 after 30 seconds:
1. Each student takes 1/4 saltine cracker and places in in the tongue in the mouth.
2. Students record their observations after 30 seconds.
3. Each student takes 1/2 cracker and chews then records their observations after 30 seconds.
Cracker Lab
1/4 after 30 seconds:
1/2 after 30 seconds:

4. After reading p. 484, students classify which activity provided evidence for physical and chemical change.
5. After reading p. 484, students then swallow the cracker and records observations after 30 seconds and classified that evidence of digestion in the esophagus
Physical: teeth grind food into smaller pieces
Chemical: Saliva breaks down food into mush

5. 6. Confirm peristalsis- the contraction and relaxation of muscles of the esophagus moving food down to the stomach- with demonstration of a ball squeezed down a tube sock.
Record what you observed.

6. front of foldable large intestine stomach small intestine Digestion
After reading p , students classify the type of changes in the stomach, small intestine and large intestine.
front of
foldable
large
intestine
stomach
small
intestine
Digestion
Physical / Mechanical
Physical / Mechanical
Physical / Mechanical
Physical / Mechanical
Inside of
Foldable
Chemical
Chemical
Chemical
Chemical

7. into chemical substances that can be absorbed and assimilated.
Inside of
Foldable
Physical / Mechanical
Physical / Mechanical
Physical / Mechanical
Physical / Mechanical
Peristalsis slows down
Muscles in the rectum release the semisolid waste from the body
Peristalsis continues to move and mix the chyme
Muscles in the stomach grind food into smaller pieces
Digestive system process where food is broken down through chewing, mixing and churning.
Chemical
Chemical
Chemical
Chemical
Gastric juice and hydrochloric acid made in stomach break apart large protein molecules
Excess water is absorbed from the chyme
Where most chemical digestion occurs: bile breaks down fat particles. Carbohydrates, proteins, and fats are broken down from bile.
the act or process
of converting food
into chemical substances
that can be
absorbed and assimilated.

8. Students create a Venn diagram to compare and contrast the evidence of physical and chemical changes in the digestive system