The nervous system normally adjusts the rate of alveolar ventilation as per the demands of the body so that partial pressure of oxygen (PO2) and partial pressure of carbon dioxide (PCO2) in the arterial blood are hardly altered, even during heavy exercise and other respiratory stress situations. Respiratory centres are classified into two types i.e. medullary and pontine. These centres contain various neurons like Dorsal respiratory group of neurons (DRG) controls inspiration and Ventral group of neurons (VRG) controls expiration along with other centres controlling the rate and depth of respiration. Reflexes like cough reflex, sneeze reflex and J reflex are mediated through these centres. Central and peripheral control of respiration is mainly regulated by PCO2 and PO2. Keywords: Alveolar Ventilation; Respiratory Centres; Cough Reflex; Sneeze Reflex; J Reflex.