Question

multiple choice question
the central chemoreceptors in the medulla oblongata respond to _.
o hydrogen ions and carbon dioxide
o hydrogen ions only
o carbon dioxide only
o hydrogen ions and oxygen

Explanation:

Central chemoreceptors in the medulla oblongata are sensitive to changes in hydrogen ion concentration. Carbon dioxide can cross the blood - brain barrier and react with water to form carbonic acid, which then dissociates into hydrogen ions. So, they respond to hydrogen ions (indirectly to carbon dioxide as it affects hydrogen ion levels). They do not respond to oxygen directly (peripheral chemoreceptors are more involved in oxygen sensing in some cases).

Answer:

hydrogen ions and carbon dioxide