Respiratory system

Objectives:

 * Summarize the functions of Human respiratory system.
 * Describing the structure and function of lungs.

Activity -
Purpose: To develop the skill of model making and describing.

1. Carry out a class discussion centred around the following questions:

a. Have you ever thought What happens how breathing takes place in our lungs? What happens to the air that we breathe in, and How do we breathe out air?

b. Name some of the important organs (or parts of the body) that are involved in respiration ?

Materials required: 2 Litre water bottle with cap, 2-3 straws, polythene cover, two balloons,

scissors, thread, glue, knife.

Instructions

Give students the following instructions:


 * Take a 2 litre water bottle; cut 3/4th the bottle as shown in the figure.


 * Take a long straw, bend 1/4th of the straw, cut a small portion of the straw at the bent surface and attach a small piece of other straw to the cut portion and stick it using a gum to make a Y-tube.


 * Tie two balloons to both the ends of the Y-tube using a thread.


 * Make a hole in the cap of the bottle and insert a Y-tube with balloons into it. Now, place it in the bottle by turning the cap.


 * Cover the bottom of the bottle using a transparent polythene cover.(Note-Bottle should not be covered tightly).
 * A model of lungs is now ready. Pull the transparent cover downwards you will see the balloons inflating, when you release the cover you see the balloons deflating.


 * Describe the structure and function of the lungs using the model created.