alleryStart learning →In respiratory physiology, a pressure written as zero means what?
AIt equals the atmospheric pressure
BIt is a complete vacuum in the lung
CIt is far below atmospheric pressure
DIt is far above atmospheric pressure
Answer & Solution
Correct answer: A. It equals the atmospheric pressure
1. Respiratory pressures are quoted relative to atmospheric pressure rather than as absolute values.
2. Negative means lower than atmospheric, positive means greater than atmospheric.
3. A value equal to atmospheric pressure is therefore expressed as zero.
4. So zero is not a vacuum, which is the trap in the second option.
_Source: OpenStax Anatomy and Physiology (CC BY 4.0), Ch 22 "The Respiratory System", section 22.3 The Process of Breathing_
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