Which hormone, secreted by the adrenal medulla during high-stress or emergency situations, increases heart rate, blood pressure, and glucose mobilization?

💡 Solution & Explanation

Adrenaline, also known as epinephrine, is secreted by the adrenal medulla in response to acute physical or emotional stress, rapidly activating the sympathetic nervous system. This hormone accelerates heart rate, constricts blood vessels to redirect blood, and stimulates glycogen breakdown to rapidly elevate blood glucose levels for immediate energy. Such physiological adaptations prepare the organism for rapid physical exertion during emergency scenarios. Human endocrine system functions are frequently tested in biology sections.