AO1

• Adrenaline is a hormone involved in a number of responses, namely flight or fight
• The stress response (otherwise known as the ‘fight or flight’ response) is hard-wired into our brains and represents an evolutionary adaptation designed to increase an organism’s chances of survival in life-threatening situations.
• The fight or flight response enables us to react quickly to life threatening situations
• The Hypothalamus activates the sympathetic nervous system . This sends a signal to the adrenal medulla.
• The adrenal medulla the releases adrenaline into the bloodstream. Adrenaline causes the body to respond to the threat. For example, heart rate, breathing, and blood pressure increase, so more oxygen reaches the heart and muscles. Additionally, glucose is realised into the blood stream to supply energy
• When the threat has passed, the parasympathetic nervous system restores heart rate and blood pressure to normal