(N/A) Regulation of respiration is achieved through two primary mechanisms:
$(A)$ Neural regulation: Humans possess a significant ability to maintain and moderate the respiratory rhythm to suit the metabolic demands of body tissues.
$1.$ $A$ specialized center present in the medulla region of the brain,called the respiratory rhythm center,is primarily responsible for this regulation.
$2.$ Another center present in the pons region of the brain,called the pneumotaxic center,can moderate the functions of the respiratory rhythm center. Neural signals from this center can reduce the duration of inspiration and thereby alter the respiratory rate.
$3.$ $A$ chemosensitive area is situated adjacent to the rhythm center,which is highly sensitive to $CO_2$ and hydrogen ions. An increase in these substances activates this center,which in turn signals the rhythm center to make necessary adjustments in the respiratory process to eliminate these substances.
$(B)$ Chemo-regulation: Respiration is also regulated by the chemical composition of blood and cerebrospinal fluid. Chemoreceptors located in the brain,aortic arch,and carotid artery recognize the levels of $CO_2$,$pH$,and $O_2$ in the blood. This information is sent to the rhythm center for remedial action. The role of oxygen in the regulation of respiratory rhythm is considered quite insignificant.