Question

What is the effect of both the sympathetic and parasympathetic nervous system innervating the same organ/effector?

• Both would stimulate the organ.

• The sympathetic and parasympathetic nervous systems never innervate the same organ/effector.

• One would inhibit the organ and one would activate the organ.

• Both would inhibit the organ.

Answer 1

The sympathetic and parasympathetic nervous system are a part of Autonomic nervous sytem. Both these nervous system has almost the exact opposite effect. The sympathetic nervous system prepares the body for intense physical activity(fight or flight) while the parasympathetic nervous sytem relaxes te body and inhibits or slows many high energy functions(rest and digest). However, there are few exceptions to this.

For instance, some of the effects of both the systems are as follows:-

PARASYMPATHETIC NERVOUS SYSTEM	SYMPATHETIC NERVOUS SYTEM
Brain activity decrease Metabolic rate decrease Stimulates flow of saliva Slows heartbeat Constricts pupil Constricts bronchi Stimulates peristalsis and secretion Stimulates release of bile Contracts bladder Stimulates erection and genitals	Brain activity increase Metabolic rate increase Dilates pupil Inhibits flow of saliva Accelerates heartbeat Dilates bronchi Inhibits peristalsis and secretion Conversion of glycogen to glucose Secretion of adrenaline and nor-adrenaline Inhibits bladder contraction Stimulates ejaculation

Therefore, the answer to this question would be that one would inhibit the organ and the other would activate the organ.