Objective: Develop understanding of the structure of the lungs and gas exchange.
All: Explain the process of breathing (4)
Most: Describe the difference between inhaled and exhaled air (5)
Some: Describe how alveoli are adapted for their purpose (6/7)
Extension: Describe how damaged alveoli can result in less gas exchange (7)
Gas exchange happens in the lungs.
You have 2 lungs, situated in your upper thorax / chest
Here, oxygen and carbon dioxide are exchanged – oxygen is needed for life and carbon dioxide is got rid of when we breathe out.
(When we breathe in we inhale)
(When we breathe out we exhale)
The outside of the alveoli is covered with tiny blood vessels.
Oxygen makes its way into thousands of special air sacs collectively called the ALVEOLI.
One of these alveoli is called the ALVEOLUS.
This is where the oxygen is transferred into the blood and carbon dioxide moves out of the blood.
If all these alveoli flattened and spread out onto the floor, they would cover an area the size of a tennis court!
Comparing inhaled and exhaled air
What are the big differences between inhaled and exhaled air?
How could you test for these?
There is another difference……
…… water vapour.
Lets take a closer look (avi)