contemporarymottledsheep: The pituitary-adrenal system

The human stress response evolved to help us survive in an environment like Africa. It helped our early ancestors to deal with predators, competition with other humans and protect offspring. It prepares the body for fight or flight by releasing energy and speeding up some physical processes.

There is a fast stress response activated by the nervous system, the sympathetic-adrenomedullary pathway and a slower stress response the hypothalmic-pituitary-adrenal system activated by the endocrine system. Both systems are activated by a stressor but the hypothalamic pituitary adrenal system is a hormone based system and prolongs the stress response by releasing energy stored in the body. It also reduces sensitivity to pain and helps the blood to clot. Both are adaptive if faced by a short term physical threat but if the stress response is activated a lot by stressors that can't be dealt with in an immediate physical way or by the way we think it can be maladaptive and cause stress related illness.

The first two video clips are part of a series on stress and show how the body responds to a stressor-Bulls. The first clip is useful for showing how the stress response is identified and measured. This is useful for understanding the type of research methods physiological psychologists use and the type of data they collect.

You need to be able to outline the hypothalmic-pituitary-adrenal system. The animation below should help you to do this. Be careful though this system causes corticosteroids to be released such as corticosterone and cortisol not adrenaline and noradrenaline.