The adrenocortical response to stress refers to the hypothalamic-pituitary-adrenal (HPA) axis. Upon the experience of a stressor, the organism's hypothalamus signals the anterior pituitary via releasing hormones, which secretes ACTH into the circulatory system. When the adrenal glands detect the ACTH, they release glucorticoids responsible for "fight-or-flight" symptoms. <img src="http://www.cns.med.ucla.edu/Images/HPAAxis.GIF"><br/>