Volume, Pressure, and Airflow

Question 1

What is Boyle’s Law?

Answer 1

Volume is inversely proportional to pressure
Increase pressure by decreasing container volume
Decrease pressure by increasing container volume

Question 2

What do we use to measure pressure?

Answer 2

Manometer (used to use water, and that’s why cmH20)

Question 3

How does intrapleural pressure change during respiration?

Answer 3

Intrapleural pressure is NEGATIVE
During inspiration, intrapleural pressure becomes
even more negative
During expiration, intrapleural pressure returns to its “resting” negative value

Question 4

What drives airflow?

Answer 4

Pressure differential
Airflow = volume change over time
Volume (L), Changes (sec) = Airflow = l/s
Gas flows from regions of high pressure to regions of low pressure
Airflow is proportional to pressure differential
Increase in pressure differential = increase in airflow