Questions: Intra-alveolar pressure is the same as atmospheric pressure during which of the following events? Check all that apply. As air flows out during expiration At rest As air flows in during inspiration When there is no air movement

The events during which intra-alveolar pressure is the same as atmospheric pressure are:

1. At rest: When the respiratory system is at rest, there is no movement of air into or out of the lungs, and the intra-alveolar pressure equals atmospheric pressure. This is because the pressures inside and outside the lungs are balanced, resulting in no net air movement.

2. When there is no air movement: This situation is similar to being at rest. When there is no air movement, the intra-alveolar pressure is equal to atmospheric pressure because there is no pressure gradient to drive air in or out of the lungs.

Explanation for each option:

• As air flows out during expiration: During expiration, the intra-alveolar pressure is greater than atmospheric pressure, which drives air out of the lungs. Therefore, intra-alveolar pressure is not equal to atmospheric pressure during this event.

• At rest: Correct. At rest, there is no air movement, and intra-alveolar pressure is equal to atmospheric pressure.

• As air flows in during inspiration: During inspiration, the intra-alveolar pressure is less than atmospheric pressure, allowing air to flow into the lungs. Thus, intra-alveolar pressure is not equal to atmospheric pressure during this event.

• When there is no air movement: Correct. When there is no air movement, intra-alveolar pressure is equal to atmospheric pressure.

In summary, intra-alveolar pressure is the same as atmospheric pressure at rest and when there is no air movement.