Question

Physiology question

You're walking around your dark house late at night, and your little brother jumps out of a closet to scare you. Your heartbeat accelerates rapidly, you pupils dilate, you feel a flush of blood rush to your muscles and the hairs on his neck and arms stood erect. After your realize it's your little brother and not a real danger, you felt greatly relieved but the body responses (heart rate, blood rushing, dilated pupils) remain for a while. What is the name of the physiological response that caused these effects and which branch of the nervous system is responsible? Why did the physiological response last longer than the stimulus?

Answer 1

The physiological response that caused these effects is known as the fight or flight response.The sympathetic nervous system that is a part of the autonomic nervous sytem is responsible.It is the sympathetic nervous system that controls the fight and flight respose.The fear stimulus received by a part of the brain known as amygdala (also known as threat centre) that transmits the signals to other parts of the brain such as prefrontal cortex, hypothalamus, sensory cortex, hippocampus,thalamus, septum and the brain stem.After this , the sympathetic nervous system is activated that results in the fight and flight responses.During the fight and flight responses , adrenal gland is activated to release the hormones epinephrine and norepinephrine which together causes the heart beat to increase , the pupils to dilate ,goose bumps and blood rush to the muscles followed by other responses as well.After realizing that it is not a danger, the parasympathetic nervous sytem is activated that brings the body to homeostatis.

                         The physiological conditions lasts longer than the stimulus because it helps to provide sufficient strength to the body in order to face the reaction and respond to it.