Every hormone in this chapter is governed by the same three-story loop: the hypothalamus signals the pituitary, the pituitary signals a target gland, and the hormone that comes out climbs back up and shuts its own bosses off. That loop cannot tell the difference between the hormone a gland made and the hormone a nurse handed over — so every dose you give is also a message to stop making it. Pick an axis, then turn the dose and the duration up and watch what happens to the patient's own gland. Tap any part of the diagram to open it up.
The loop, at rest
Pituitary signal
Gland output
Total hormone effect
Target gland
One loop, four axespick an axis, then turn the dose up
Exogenous drug dose none
nonereplacelowhighvery high
How long it has been given single dose · under 1 week