A pedestrian narrowly avoids being hit by an oncoming car. He notices that it takes a little while for hisheart rate and respiratory rate to return to normal. This is likely because
A) the parasympathetic nervous system has become activated.
B) sympathetic activation of the adrenal medulla has released epinephrine and norepinephrine into the bloodstream.
C) the splanchnic nerves have become activated.
D) somatic motor neurons have increased the heart and respiratory rate.
E) the corticospinal pathway has become activated.

Question

Quizplus · Accepted Answer

The sympathetic nervous system is responsible for the "fight or flight" response, which causes an increase in heart rate and respiratory rate due to the release of epinephrine and norepinephrine from the adrenal medulla. It takes some time for these hormones to clear from the bloodstream and for the parasympathetic nervous system (which slows down bodily functions) to take over, allowing the heart rate and respiratory rate to return to normal.

A Pedestrian Narrowly Avoids Being Hit by an Oncoming Car