This introduction covers The Story: The Emergency Broadcast within Hormones & Behaviour for GCSE Biology. Topic 8: Hormones & Behaviour It is section 1 of 10 in this topic. Use this introduction to connect the idea to the wider topic before moving on to questions and flashcards.
The Story: The Emergency Broadcast
Imagine your brain is a newsroom. The moment a threat is detected — a near-miss on a bike, the moment before you walk on stage — the newsroom sends an emergency broadcast straight to your adrenal glands. Within seconds, adrenaline floods your bloodstream. Your heart hammers. Your breathing quickens. Your muscles are primed. Your body has just been told: "Emergency. Act now." This is adrenaline — the hormone of behaviour, urgency, and survival.
Meanwhile, a quieter hormone, thyroxine, runs a slower but equally vital service: it sets the background pace of every chemical reaction in every cell of your body, day and night, adjusting your metabolic rate to match what life demands.
Practice questions for Hormones & Behaviour
Which response does adrenaline prepare the body for?
State two effects of adrenaline on the body during a fight-or-flight response.