1.  Materials

a.  Paper

b.  Pencils

c.  To “build” the lungs

                            i.   6" x 4.5" (¼ sheet) piece of pink or gray construction paper (trachea)

                            ii.  plastic 2-liter soda bottle with black bottom cut off (thoracic cavity)

                            iii.  two round 9" or 12" pink balloons (lungs)

                            iv.  two drinking straws (bronchi)

                            v.   medium-sized plastic bag large enough to fit over bottom end of bottle (diaphragm)

                            vi.  3 or 4 cotton balls

                            vii.  transparent tape

                            viii.  medium-size, thin rubber band

d.  Resources:

                            i.  http://www.adprima.com/sci-respsystem.htm

             2.  Objectives

a.  Students will analyze a lung model and describe the function of the diaphragm in the respiratory system.

             3.  Motivation

a.  Have students lie quietly on the floor with their hands on stomachs. Ask them to be as silent as possible and focus only on their breathing. As students are inhaling and exhaling ask them to pay special attention to any parts of their body that are moving as they breathe. After a few minutes have students discuss what they saw or felt. Some students, not all, will have seen or felt their stomachs moving up and down as they breathed.

b.  If no students have noticed the movement, have them watch as I breathe in and out. Tell students there is a muscle that forces us to breathe in and out and sometimes when you breathe it is noticeable. Not all people breathe with their diaphragms, but musicians do because that’s how they can control their air supply. All babies breathe this way as well until they grow out of it. You get a higher quality and quantity of air when you learn to breathe deeper instead of just using shallow chest breaths.

             4.  Goal for Learner

a.  Today we will learn about the function of the diaphragm in the respiratory system.

             5.  Content and Procedures

a.  Teacher Content

                            i.  Oxygen enters the body through the nose or mouth and goes down the trachea (or windpipe) into the lungs. The oxygen enters the lungs through two bronchial tubes (one for each lung). The lungs are then inflated and deflated when the diaphragm (located below the lungs) pulls and pushes on the lungs.

b.  Procedure

                            i.  Begin building the model lungs for students. The steps are listed below:

1.  Insert straws into balloons and tape together at top. These are bronchi and lungs.

2.  Insert these through open bottom of modified 2-liter soda bottle straw end first and bring ends of straws up through the neck of the bottle.

3.  Stuff neck of soda bottle with cotton balls around straws until spaces are plugged.

4.  Roll construction paper into a tube just round enough to fit over the tops of the straws. Tape closed and place over tops of two straws. This will be the trachea.

5.  Place plastic bag over bottom end of bottle and use the rubber band to hold it in place. This will serve as the diaphragm.

6.   Grasp bottom of plastic bag and pull down and push up. Watch as the “lungs” expand and contract as you do this.

                            ii.  Discuss the individual steps while creating the “lungs” so students understand what each part represents. Allow students to manipulate the model in order to fully understand the function of the diaphragm on the lungs.

             6.  Practice/Application

a.  Students will complete the two “Respiratory System” pages found within their folder. One includes a diagram of the system, labeling parts such as the nasal passage, pharynx, epiglottis, larynx, trachea, alveoli, bronchioles, diaphragm, and lungs. The second page explores the workings of the Respiratory System.

b.  Students will also explain in a paragraph of no less than 4 sentences the function of the diaphragm in respiration and will include the terms expand, contract, inhale, and exhale (or variations of those terms) as they relate to the diaphragm and lungs. For example, when the diaphragm contracts air is inhaled and the lungs expand with air. When the diaphragm expands, the lungs contract and the air is expelled or exhaled.

             7.  Evaluation of Student Learning

a.  The pages from the folder will be graded based on accuracy and completion at the end of the unit when the entire folder is graded.

b.  The respiratory system paragraphs will be graded based on accuracy and completion. Students should describe the function of the diaphragm in the respiratory system process as indicated above.

             8.  Closure

a.  Allow students to make predictions and then test what would happen if they were to bend the “trachea” and “bronchi” over. The air supply will be cut off resulting in nothing happening when the “diaphragm” is manipulated.