Apneustic centre and inspiratory ramp signals.

Apneustic Centre

This area is so named because if the brainstem of an experimental animal is sectioned just above this site, prolonged inspiratory gasps (apneuses) interrupted by transient expiratory efforts are seen.

Inspiratory ramp signal

The neurons in the DRG sets up the inspiratory ramp signal.

Inspiratory ramp signal- The neural signals transmitted to the inspiratory muscle, mainly the diaphragm, is not instantaneous burst of action potentials. Instead, it begins weakly and increases steadily in a ramp manner for about 2 seconds in normal respiration. Then, it ceases abruptly for approximately next 3 seconds which turns off the excitation of the diaphragm and allows elastic recoil of the lungs and the chest wall to cause expiration. Next, the inspiratory ramp signal begins for another cycle.