So lets talk a little more bout it and add that valuable information from this member.

1-Central chemoreceptors in the medulla will be sensitive to what?
2-Peripheral chemoreceptors in the carotid and aortic bodies will be sensitive to what?

1-CO2 and H, now remember that H will not cross the blood brain barrier as well CO2 does .

So a change in H will affect the ph and the ph will directly affect the central chemoreceptors in the medulla by the CSF.
Also remember that CO2 is lipid soluble so will readily cross the blood-brain brarrier.