Reading Checks (Page 339)
When is the air pressure in the lungs less than the air pressure outside the body?
When you inhale.
When is the air pressure in the lungs greater than the air pressure outside the body?
When you exhale.
What is the function of the diaphragm?
A sheet of muscle in the lower chest that moves downward as you breathe in.
What are the two causes of swelling within the respiratory system?
Bacteria, viruses, and other micro-organisms. Also breathing in smoke, polluted air, coal dust and asbestos.
What happens in an asthma attack?
The pathway to the lungs becomes too narrow, making it difficult to breathe.