Neuroendocrine control of blood tonicity and volume

The numerous studies cited in this chapter clearly show that very complex mechanisms are involved in the cardiovascular and osmotic regulation of AVP release. Information from peripheral receptors within the cardiovascular system and from central osmoreceptors is carried by multisynaptic neural inputs to the SON and PVN. This information is co-ordinated at one or more sites within the hypothalamus, the brain stem, or even the neurohypophysis itself, to ensure release of the appropriate amount of AVP. In many cases the origin of the pathway and the nature of the neurotransmitter is known, but further studies are needed to establish their physiological role in AVP release.