You go to your next class, but because you're so full from lunch, you doze off. you awake to your classmate poking you in the arm as you realize the teacher is calling your name to answer a question. with your heart racing, your body now releases , which increases glycogen breakdown in the liver and raises your blood sugar.

Epinephrine (adrenaline)

Explanation:

Epinephrine also referred to as adrenaline, is a hormone that is usually produced by the medulla of adrenal glands into the bloodstream when the body perceives  stimuli such as fear. When epinephrine is secreted into the bloodstream, it causes an increase in sugar metabolism, increases heart rate and blood pressure, and helps in improving blood flow. These responses are in reaction to the perceived danger which seeks to put the body in a “fight or flight” mode. The sympathetic nervous system controls these actions.