Question

Central chemoreceptors are stimulated by __________.

a) H+ ions that cross the blood-brain barrier
b) H+ ions in arterial blood
c) H+ ions produced in cerebrospinal fluid from CO₂ that crosses the blood-brain barrier
d) none of the above

Answer 1

Central chemoreceptors are stimulated by H+ ions produced in cerebrospinal fluid from CO2 that crosses the blood-brain barrier, which in turn leads to an increase in respiration rate and depth.

Step-by-step explanation:

Central chemoreceptors are stimulated by c) H+ ions produced in cerebrospinal fluid from CO₂ that crosses the blood-brain barrier. As the concentration of CO₂ in the blood increases, it readily diffuses across the blood-brain barrier and is converted into hydrogen ions and bicarbonate in the cerebrospinal fluid, leading to a decrease in pH.


This increase in hydrogen ions stimulates the central chemoreceptors, which then signal the respiratory centers to increase the rate and depth of respiration. This helps in expelling more carbon dioxide out of the lungs, thereby reducing the levels of carbon dioxide and H+ ions in the blood and in the cerebrospinal fluid, helping to normalize the pH levels.