Download Upper Digestive System

Upper Digestive System
A Guided Inquiry Lesson
This lesson plan may be used to address the academic standards listed below. These National
Science Education Standards are drawn from Content Knowledge for Life Science. The science
subject matter focuses on the science facts, concepts, principles, theories, and models that are
important for all students to know, understand, and use.
Subject: Science; Grades 2-4
Purpose: Students will to know the parts of the digestive system, their functions, and where the
organs are located.
Student Learning Outcomes: Students will be able to describe the parts and functions of the
upper digestive system either written or orally with 3 of the 6 components correct.
Prior Knowledge: Students know the human body is made up of systems that function together
to keep the body in working order.
Materials:
Students and Teacher
 Stomach slide
 Digestive system slide
 Mouth slide
 Esophagus slide
 Human body model
 Quart carton
 Guided Tour of Digestion
 Water
 Hand held human model
Technology Needed:
 Elmo
 Internet Connection
Behavior Expectations: Today we will be performing an experiment. Some of the materials we
are going to use are expensive. I expect you to be careful and abide by the safety rules when
using the materials. I expect the proper clean-up after the lesson.
Motivation:
What do you think the digestive system does?
Where do you think your breakfast is right now? How long will the food stay there? How does
food become small enough to swallow? Today we are going to learn about the first three parts of
the digestive system: the mouth, throat, and stomach. Later this week we will learn more about
other parts of the system. Let’s watch a little video clip on your digestive system.
http://www.brainpop.com/health/digestivesystem/digestion
Data Collection:
1. Students will label a digestion diagram and write two sentences describing each of the
following parts: mouth, throat, and stomach.
2. Students will write an essay about the human body (see attachment for details).
Data Collection Procedure:
The first part of the system we will talk about is the mouth. This is where digestion begins. What
do you think the mouth does to begin digestion? (Allow students to tell you their ideas. Record
them on the board.) In the mouth there are many important organs including the tongue, teeth,
and the salivary glands (the spit makers). (Place mouth slide on overhead, point to students to
make suggestion.) The tongue is used to move food around for chewing and it helps form the
food into a rounded mass called a bolus. The rounded mass makes the food easier to swallow.
Each type of tooth has a different job. What do you think those jobs might be? (Student may say
chew, rip, grind, etc.) The molars, the teeth in the back, grind the food. The canines rip the food.
Those are the only teeth we are going to talk about today. The teeth help cut and grind food into
small pieces. As it is being ground saliva is mixed into it. The salivary glands are used to keep
the inside of the mouth moist, but when you eat, the amount of saliva increases and this begins
the chemical breakdown of the food. Digestion actually begins in the mouth.
Debriefing and Checking for Understanding:
Data Processing:
There are many interesting facts about spit. It is 99.5% water. The water allows the food to be
tasted and the other chemicals begin the breakdown of the food.
How much saliva do you think you produce in a day? (Allow students to make hypothesis, ask
them to explain why they think that.) The glands produce 1½ quarts of saliva a day. (Show an
example of a quart and how much “spit” that would be with water.)
After the food is swallowed in its rounded shape, the food travels down the throat with help from
muscle contractions called peristalsis. This journey down the throat takes 5-10 seconds. (Show
picture of the bolus being swallowed.) Have you ever swallowed something and felt it move
down your throat? What was it that you swallowed? Why do you think you could feel it more
than something else?
The final part of the digestive system we are going to talk about today is the stomach. The
stomach is where the majority of digestion happens. The stomach is “J” shaped (show on the
human body figure where this is, place up close stomach slide on overhead). The top of the “J” is
where the food bolus drops into the stomach. The bottom of the “J” is where the partially
digested food enters the small intestine. We will talk about the small intestine tomorrow. Once
the food is in the stomach it is digested with juices and acids. These juices are called gastric
juices. This stomach acid is very strong and the inside of the stomach has a protective layer of
membrane. The juices begin when the food is dropped into the stomach. The stomach makes
rippling movements that are called mixing waves. When this happens your stomach may rumble
or gurgle. Have you ever felt or heard your stomach growl? At the end of the 2-3 hours of
stomach mixing, the food is reduced to a thin watery liquid called chime. The chime is then
slowly allowed into the small intestine.
What are the parts of the mouth we talked about today?
What is one thing you find interesting about the saliva in the mouth?
What shape does food travel down the throat in?
Describe the shape of the stomach. Explain how this shape helps it to function.
How are stomach juices helpful?
Appraisal:
Class Participation
Descriptive sentences (two sentences on each part: mouth, throat, stomach)
Completion of the Diagram (coloring)
Extended Practice:
Color a version of the digestive system however you believe you will best be able to remember
it. Write a brief description of each part we talked about today. Use the class computers or one at
home to go to this website to learn more: http://www.medtropolis.com/VBody.asp.
References:
Guided Virtual Tour PC tour of digestion. http://www.medtropolis.com/VBody.asp
Kapit, W. & Elson, L. M. The Anatomy Coloring Book, p. 98 (worksheet)
Torlora, G. J., Grabowski, S. R. Principals of Anatomy and Physiology 7th Edition (1993).
HaperCollins College Publisher, pp. 767-785.
Van Cleaves, J. The Human Body for Every Kid (1995). John Wiley & Son’s, Inc.: New York.
http://www.brainpop.com/health/digestivesystem/digestion
Additional Reading:
Bingham, C. & Wright-Smith, S. The Amazing Pull-Out Pop-Up Body in a Book (1997). A DK
Publishing Book.
Cole, J. The Magic School Bus: Inside the Human Body (1989). Scholastic: New York.
Jeunesse, G. & Perols, S. The Human Body (1995). Scholastic: New York.
Digestive System Data Collection Sheet
Some parts in the mouth are the _________________, _________________, ________________
The tongue does:
The rounded mass of food is called a _________________.
Teeth ________________ and ___________________ food.
Salivary glands do:
Some interesting things about saliva:
1.
2.
The journey of food from the mouth to the stomach takes __________________ seconds.
The stomach is ____________ shaped.
Juices in the stomach are called ___________________.
Food stays in the stomach _________________.