THE SYMPATHOMEDULLARY PATHWAY
This system uses electricity (i.e. communication along nerve fibres) and is very fast indeed, faster than the chemical-based pituitary-adrenal system.
HOW IT WORKS
•Hypothalamus activates sympathetic branch of the ANS.
•The sympathetic branch sends a signal to the adrenal medulla.
•In response, the adrenal medulla releases adrenaline and noradrenaline.
•These contribute to the stress response e.g. increasing blood pressure and heart rate.