In the stressed condition body in stressed or harmful event, or life threatening situation the body in response perceive some physiological changes. In the acute stress the sudden hormone release the body activate sympathetic nervous system.
The activated nervous system stimulate the adrenal gland release noradrenaline and adrenaline hormones.
Thus, the correct answer is - fight or flight reaction.
The nervous system and hormonal system of the body work together to maintain the normal physiology and homeostasis of the body. The body can bring some internal changes depending on the external situation.
The fight and flight condition of the body may arise in case of any frightened situation. On seeing the bear, the body's fight and flight mechanism starts to cope with the situation. The epinephrine hormone brings changes via activating the autonomic nervous system of the body. The heart beat fast, pupils dilated and the blood flow increases in the body.
