Skip to main content
. Author manuscript; available in PMC: 2015 Apr 1.
Published in final edited form as: Compr Physiol. 2014 Apr;4(2):739–769. doi: 10.1002/cphy.c130035

Figure 7.

Figure 7

Adrenal insufficiency. In primary adrenal insufficiency, the adrenal cortex is typically destroyed (indicated by an X). This relieves the hypothalamus of cortisol negative feedback such that, presumably, corticotrophin-release hormone (CRH) is increased, although sampling portal vein blood is not possible in humans. The loss of negative feedback at the pituitary leads to a large increase in plasma ACTH. In secondary adrenal insufficiency, adequate ACTH secretion is lost (indicated by an X) resulting in suboptimal plasma ACTH and adrenal atrophy.