How it works
To label the bell jar model, write a name on the line for each number. The numbers ring the jar, the tube through its neck, the two balloons and the sheet tied across its open base.
Read the full guide
Bell jar model word bank
In alphabetical order: balloons, bell jar, glass tube, rubber sheet, stopper, Y-tube branches.
The numbers that get swapped
Two numbers sit on one piece of glass. The one above the neck is on the straight stem, the glass tube. The one inside the jar is on an arm of the fork, the Y-tube branches. At the neck, the dark plug is the stopper and the clear wall below it is the bell jar. At the base, the number is on the curved band tied across the opening, the rubber sheet.
- The knob in the middle of the sheet and the arrow under it are drawn, but have no number.
- A second task for the same sheet: beside each name, write the part of the chest it stands for. The stopper stands for none.
- When marking, sheet rubber or membrane is right for the rubber sheet: older manuals use both.
Questions and answers
How do you make a bell jar model of the lungs?
A school laboratory manual of 1911 lists the parts: a small bell jar with an opening at the top for a rubber stopper, sheet rubber tied over the base, and a Y-tube with a toy balloon on each branch, its stem passing through the stopper.
What is the knob on the rubber sheet for?
It is the place to grip. In the 1911 manual a piece of chalk in the center of the rubber forms the knob, and the model is worked by catching it and pulling it down.
Is breathing in or breathing out the active phase?
Breathing in. It results from muscle contraction: the diaphragm contracts and the chest cavity grows. Quiet breathing out follows when the diaphragm relaxes and elastic tissue recoils. On the model, a hand pulls the sheet down, then lets it go.
Does the bell jar model worksheet have an answer key?
Yes. The key prints the model with its numbers and lists the six names in order, from balloons to stopper.