Biology / Unit 13 Bio 3171 short lesson, about 20 seconds
Rising CO2 and Falling pH Drive the Breathing Reflex
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The idea
Central chemoreceptors detect rising carbon dioxide and falling pH in cerebrospinal fluid, per Bio 3167, and signal the brainstem to raise breathing rate before oxygen drops critically.
In practice
A rebreathing bag raises inhaled carbon dioxide and quickly drives faster breathing despite ample oxygen.
Where people slip
"Breathing is driven by low oxygen," per Bio 3169, ignores that oxygen sensors serve only as backup.
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