The document describes how lungs work with the help of the diaphragm muscle. It explains that inhaling occurs when the diaphragm contracts, pulling down and expanding the chest cavity so that air is drawn into the lungs. Exhaling happens when the diaphragm relaxes and the chest cavity decreases in size, pushing the air out of the lungs. The diaphragm is essential to breathing by controlling the movement of air in and out of the lungs.

1. Activity 2

2. 
 Explain how the lungs work
 Describe how the movement
of the diaphragm helps the air
go in and out of the lungs
Objectives:

4. 
Inhale
Exhale

5. 

6. 
 Q4. What does each part of the constructed lung
model represent?
The bottle serves as the chest cavity, the straws are the
bronchi, two small balloons as the lungs and the big balloon as the
diaphragm.
 Q5. What happens as you pull down the balloon at
the bottom of the model?
When we pull down the big balloon(diaphragm) at the
bottom of the model it contracts, causing the small balloons (lungs)
to expand/to be fill in with air.
Guide Questions:

7. 
 Q6. What happens as you push up the balloon?
When we push up the big balloon(diaphragm) at the
bottom of the model it expands, causing the small balloons (lungs)
to contract/to release air.
 Q7. How does the movement of the diaphragm
cause the air to go in and out of the lungs?
As the diaphragm goes down(contracts) it causes the air to
go into the lungs and as it goes up(expands), the air goes out of the
lungs.
Guide Questions:

8. 
Q8. What might happen if you prick
the balloon?
If the balloon is pricked that serves as the
diaphragm it can’t do its function. Meaning the
system will not work properly.
Guide Questions:

10. 
Inhalation and exhalation are the processes by which the body brings in
oxygen and expels carbon dioxide. The breathing process is aided by a large dome-
shaped muscle under the lungs called the diaphragm.
When you breathe in, or inhale, the diaphragm muscle contracts.
Inhaling moves the diaphragm down and expands the chest cavity. Simultaneously,
the ribs move up and increase the size of the chest cavity. There is now more space
and less air pressure inside the lungs. Air pushes in from the outside where there is
a higher air pressure. It pushes into the lungs where there is a lower air pressure.
When you breathe out, or exhale, the diaphragm muscle relaxes. The diaphragm
and ribs return to their original place. The chest cavity returns to its original size.
There is now less space and greater air pressure inside the lungs. It pushes the air
outside where there is lower air pressure.
Lungs can’t work without the diaphragm, because it is the one that
controls the flow of air in and out of it. It is impossible for the lungs to perform
without the diaphragm.
We therefore conclude that:

11. GROUP 1-
ACACIA