If the brain continues to perceive something as dangerous, the hypothalamus releases corticotropin - releasing hormone (CRH), which travels to the pituitary gland, triggering the release of adrenocorticotropic hormone (ACTH). (health.harvard.edu)
[2] It has also been shown to increase the release of adrenocorticotropic hormone (ACTH), which stimulates an increase in adrenal hormone secretion. (chiro.org)
In the normal response to a stressful situation, the hypothalamus in the brain sends corticotropin - releasing hormone (CRH) to the pituitary gland, which releases adrenocorticotropic hormone (ACTH) to the adrenal gland. (scientificamerican.com)