Blood Gas Regulation
The control of the levels of oxygen and carbon dioxide in the blood — ensuring cells receive enough oxygen and that carbon dioxide, the main waste of metabolism, does not accumulate.
What is sensed
Section titled “What is sensed”Specialized chemoreceptors monitor the blood. Notably, the strongest moment-to-moment driver of breathing is not low oxygen but rising carbon dioxide, which the brainstem detects very sensitively.
How it is regulated
Section titled “How it is regulated”The brainstem adjusts the rate and depth of breathing:
- Rising carbon dioxide (or falling oxygen) speeds and deepens breathing, expelling CO2 and taking in O2.
- Falling carbon dioxide slows breathing.
Key idea
Section titled “Key idea”Blood gases are regulated almost entirely by adjusting breathing, and the controlling signal is mainly carbon dioxide — which is also why this system is bound up with acid–base balance.