Final answer:
The fight-or-flight response is regulated by the sympathetic division of the autonomic nervous system, involving the release of adrenaline and noradrenaline which prepare the body for quick reaction to a perceived threat, an adaptation for survival.
Step-by-step explanation:
The fight-or-flight response is dominated by the sympathetic division of the autonomic nervous system. When faced with a threat, this response is triggered, prompting the adrenal glands to release epinephrine (adrenaline) and norepinephrine (noradrenaline), resulting in various physiological reactions. These reactions include increased heart rate, dilation of pupils, slowed digestion, and heightened blood glucose levels, preparing the body to either confront or escape the danger. This response is deeply ingrained in the nervous system and is a common trait among many animals.
Significantly, Walter Cannon coined the term 'fight-or-flight' in 1915 to describe this biological response to threatening situations. The response is intended to maintain homeostasis in the face of stressors. It represents an evolutionary adaptation that enables both humans and animals to rapidly mobilize energy and resources in order to increase the chances of survival.