Building A Model Lung

1. Design your own working model of the lung using the materials given below:

transparent plastic bottle, balloon, rubber sheet (plastic glove), clay, Y-tube, tape/ rubber band, other accessories

2. Complete the handout for the model building activity.

The Mechanics of Breathing

DIAPHRAGMDome-shaped muscle attached to rib cage that contracts& flattens out during breathing

Observe what happens to the diaphragm.

PRESSUREforce of air pressing down

Less air particles- Low air pressure

More air particles- High air pressure

High to Low Pressure

(Many to Less)

How do you change the pressure?

Air pressure (outside air)

Air pressure (empty space)

Air pressure (inside balloon

Breathing – The Lungs

• Breathing animation

"nature hates a vacuum"

http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html

Breathing in - inhaling• Rib cage– expands

• Diaphragm– moves downward

• Pressure– reduces inside lung

• Result – air is drawn into the lungs

Breathing out - exhaling• Rib cage– contracts

• Diaphragm– moves upward / inward

• Pressure– increases inside lung

• Result – air is pushed out of the lung

BREATHING

Breathing – The Lungs• Breathing animation

Write a paragraph explanation/ summary on how breathing works. Discuss the role of the ribcage and the diaphragm and how these creates a pressure difference so breathing can take place.

"nature hates a vacuum" http://www.biosci.ohiou.edu/introbioslab/Bios170/diffusion/Diffusion.html