Can you explain the physiological basis of the stress response and the role of the hypothalamic-pituitary-adrenal (HPA) axis in coordinating hormonal adaptations to stressors? How does the hypothalamus detect stress signals and release corticotropin-releasing hormone (CRH), stimulating the anterior pituitary gland to produce adrenocorticotropic hormone (ACTH) and trigger cortisol secretion from the adrenal cortex? Additionally, how does cortisol exert its effects on target tissues to mobilize energy reserves, suppress inflammation, and modulate immune responses during acute and chronic stress? Furthermore, how do dysregulations in the HPA axis contribute to stress-related disorders like anxiety, depression, and post-traumatic stress disorder (PTSD)?