Vagal stimulation causes: September 2009

Ans. D: Decreased depth of respirationAlthough the rhythmic discharge of medullary neurons concerned with respiration is spontaneous, it is modified by neurons in the pons and afferents in the vagus from receptors in the airways and lungs. An area known as the pneumotaxic center in the medial parabrachial and Kolliker-Fuse nuclei of the dorsolateral pons contains neurons active during inspiration and neurons active during expiration.Stretching of the lungs during inspiration initiates impulses in afferent pulmonary vagal fibers. These impulses inhibit inspiratory discharge.