Multiple mechanisms appear to be involved in mediation of increased secretion of cortisol after hemorrhage. Signals from cardiovascular receptors are transmitted to the hypothalamus through ascending neural pathways to release ACTH. Angiotensin II stimulates release of ACTH by an action on the median eminence, but does not stimulate adrenal secretion of cortisol directly. However, secretion of cortisol can increase rapidly after hemorrhage without changes in ACTH. Common afferent pathways probably mediate all these mechanisms.