Adrenaline is responsible for fight-or-flight response in our body. It is produced in the medulla of the adrenal glands. During a stressful situation, it is quickly released into the blood and sending impulses to the organs for a specific response. There are many effects of Adrenaline in our body such as the increase in heart rate, increase of blood pressure, expanding lung's air passages, and enlarging the pupil in the eye.