Once activated the HPA-axis starts its response instantly, causing the the pituitary gland to create and release hormones.

The adrenal glands are stimulated by ACTH to release ... this cycle and suppression of its activity. Suppression of the HPA axis affects a patient's ability to respond to an acute stressful ...

Cortisol is a steroid hormone produced by your two adrenal glands, located on top of each ... can disrupt neurotransmitter function and the HPA (hypothalamic-pituitary-adrenal) axis, reducing ...