In: Anatomy and Physiology
1. Are the lungs innervated by both the sympathetic and parasympathetic nervous system? How about the eyes? And the heart?
ANSWER :
Both the sympathetic and parasympathetic division of the autonomic nervous system (ANS) innervate to the lungs, eyes and the heart, & other many visceral organs in the body. The parasympathetic nerve branches arise from the vagus nerve innervate the lungs and cause their bronchoconstriction, while sympathetic nerves from the upper thoracic and cervical ganglia of sympathetic trunk innervate the lungs to cause bronchodilation.
The sympathetic nerve branches innervate both the eyes and initiate the pupillary dilation, while parasympathetic division performs its action to constrict pupils of the eyes according to variable light conditions.
The nerve branches of both the division of ANS innervate to the specific region of the heart, but they differ in their action to regulate the heart function. The sympathetic division accelerate the heart rate via releasing acetylcholine (ACh) neurotransmitter through vagus nerve during fight or flight responses, while the parasympathetic division is responsible for decreasing the heart rate to get the normal level.