The HPA axis relies on a series of hormonal signals tokeep the sympathetic nervous system. If the braincontinues to perceive something as dangerous, thehypothalamus releases Corticotropin-ReleasingHormone (CRH), which travels to the pituitary gland,triggering the release of AdrenocorticotropicHormone (ACTH). This hormone movements to theadrenal glands, prompting them to release Cortisol.The body thus stays on high alert.