Explain (HT only) how adrenaline increases heart rate and increases oxygen and glucose delivery to the brain and muscles.

In the subtopic Feedback systems (HT only), this learning objective focuses on explain (HT only) how adrenaline increases heart rate and increases oxygen and glucose delivery to the brain and muscles. Within Hormonal coordination in humans, students should explain this idea in the exact curriculum context rather than as an isolated fact. Approved keywords for this objective include adrenaline, glucose, heart rate, and HT only. adrenaline means a hormone secreted by the adrenal glands that increases heart rate and enhances oxygen and glucose delivery to the brain and muscles during stress or fear. Avoid students often state that adrenaline only increases heart rate without mentioning its role in oxygen and glucose delivery; instead emphasize that adrenaline not only increases heart rate but also enhances the delivery of oxygen and glucose to the brain and muscles, which is crucial for the body's response to stress or fear. For exam answers, focus on how adrenaline affects heart rate and oxygen delivery during stress or fear. Create a diagram to visualize this process.