Answer
Hormone signaling in response to environmental changes are crucial to the survival of all animals. In major ways, epinephrine and norepinephrine are excreted to stimulate a response to danger, triggering the sympathetic nervous system to reroute body functions to focus on protection and flight.
Work Step by Step
In more minor ways, environmental signaling moves the body through the general functions necessary to sustain life and promote health. At night, melatonin is produced in daytime-active animals to encourage sleep. Aldosterone and other mineralcorticoids are released in response to osmoregulatory needs, maintaining water and mineral balance in the body.