Question

Chemosensitive area of respiratory centre in medulla is affected by 

(a) less CO₂ and H⁺ ions 

(b) less O₂ and H⁺ ions 

(c) excess CO₂ and H⁺ ions 

(d) excess O₂ and H⁺ ions.

Answer 1

The correct option is (c) excess CO₂ and H⁺ ions.

Explanation:

Human beings have a significant ability to maintain and moderate the respiratory rhythm to suit the demands of the body tissues. A specialised centre present in the medulla region of the brain called respiratory rhythm centre is primarily responsible for this regulation. A chemosensitive area is situated adjacent to the rhythm centre which is highly sensitive to CO₂ and hydrogen ions. Increase in these substances can activate this centre, which in tum can signal the rhythm centre to make necessary adjustments in the respiratory process by which these substances can be eliminated.