Sympathetic and parasympathetic neural actions

Question

Describe the antagonism between the sympathetic and parasympathetic neural actions?

Answer 1

In general, the actions of sympathetic and parasympathetic are antagonistic, that is, while one stimulates something the other restrains and vice-versa. The organs, with some exceptions, get efferences from such two systems and the antagonism among them serves to modulate their effects. For illustration, the parasympathetic stimulates salivation whereas the sympathetic inhibits it; the parasympathetic constricts pupils whereas the sympathetic dilates it; the parasympathetic contracts the bronchi whereas the sympathetic relaxes them; the parasympathetic excites the genital organs whereas the parasympathetic restrains the excitation.