How epinephrine work during the stress response?

Fight & flight. In response to a perceived threat, Epinephrine prepares your body to fight with or flee the predator/other aggressor. It signals your heart to pump harder, increase blood pressure, open airways in the lungs, narrow blood vessels in the skin and intestine to increase blood flow to major muscle groups, and works with other stress hormones like cortisol. It's adaptive acutely, but not chronically.