Question

question 88 (0.5 points)
if atmospheric pressure is 760 mmhg and intrathoracic pressure is 758 mmhg, which of the following would you expect to happen?
○ because atmospheric pressure is lower, air will exit the lungs.
○ because intrathoracic pressure is higher, air will enter the lungs.
○ because atmospheric pressure is higher, air will exit the lungs.
○ because intrathoracic pressure is lower, air will enter the lungs.

Explanation:

To solve this, we compare atmospheric pressure (760 mmHg) and intrathoracic pressure (758 mmHg). Air moves from high - pressure to low - pressure areas. Since intrathoracic pressure (758 mmHg) is lower than atmospheric pressure (760 mmHg), air will flow from the atmosphere (higher pressure) into the lungs (lower intrathoracic pressure). Let's analyze each option:

• Option 1: Atmospheric pressure (760 mmHg) is higher, not lower, so this is incorrect.
• Option 2: Intrathoracic pressure (758 mmHg) is lower, not higher, so this is incorrect.
• Option 3: If air exits the lungs, the pressure inside the lungs should be higher than atmospheric pressure, but here atmospheric pressure is higher, so this is incorrect.
• Option 4: Intrathoracic pressure is lower (758 mmHg < 760 mmHg), so air moves from the higher - pressure atmosphere into the lungs. This option is correct.

Answer:

Because Intrathoracic pressure is lower, air will enter the lungs.