Lesson 9 of 11 · 7 min
Regulation of respiration
NCERT §14.5
Meher crosses the finish line and her legs stop, but her chest keeps heaving hard for another minute. Something in her brain is still driving that.
The lesson in notes
In short
Humans can adjust their breathing rhythm to match the body's demands; the neural system does this.
This regulation is mainly the job of a specialised centre in the medulla of the brain, called the respiratory rhythm centre.
The rhythm centre can be moderated by the pneumotaxic centre in the pons. Its signals can reduce how long inspiration lasts, which changes the breathing rate.
A chemosensitive area next to the rhythm centre is highly sensitive to CO₂ and hydrogen ions. A rise in these activates it, and it signals the rhythm centre to adjust breathing so these substances are removed.
Receptors associated with the aortic arch and the carotid artery also detect changes in CO₂ and H⁺ concentration and send signals to the rhythm centre.
Oxygen plays only a very minor part in setting the rhythm of breathing.