Answer the following question given this paragraph: 

Pressure Relationships Inspiration (or inhalation) and expiration (or exhalation) are dependent on the differences in pressure between the atmosphere and the lungs. In a gas, pressure is a force created by the movement of gas molecules that are confined. For example, a certain number of gas molecules in a two-liter container has more room than the same number of gas molecules.


Q: Pressure relationships inspiration (or inhalation) and expiration (or exhalation) are dependent on the differences in pressure between the atmosphere and these?


A:
lungs