Apneusis occurs when transection is-

Ans. is 'b' i.e., Midpontine Effect on respiration by transection at different levels of brain1) Transection above pons has no effect on respiration.2) A mid pontine transection (Transection between upper and lower pons) or damage to pneumotaxic center.i) When vagi are intact:# The inhibitory effect of pneumotaxic center on apneustic center is abolished. However, inhibitory effect of vagus is intact. Therefore, the activity of apneustic center is increased a little bit which results in prolongation of inspiratory ramp. Thus , breathing becomes deep and slow. But there is no change in rhythm.ii) With bilateral vagotomy:# This eliminates the inhibitory influence of both pneumotaxic center and vagi on the apneustic center. The uninhibited effect of apneustic center results in sustained gasping inspiration which is interrupted by brief inefficient expiration, i.e., Apneusis.3) Transection atpontomedullary junction: - Spontaneous respiration is maintained because the respiratory rhythm is generated in medulla which regulate the discharge of DRG and if required VRG. However, respiration is slight irregular and gasping.4) Transection below the medulla : - Respiration is stopped completely.5) Bilateral vagotomy (without any brain lesion): - Inhibitory effect of vagi on apneustic center is abolished; however, inhibitory effect of pneumotaxic center remains intact. Therefore, there is slight increase in activity of apneustic center. Thus breathing is deep and slow.