D-1


Where are the osmoreceptors located that initiate drinking? Yes, the acronym OVLT, a circumventricular organ. Where is it located? On the blood side of the blood-brain barrier. Again, actual location is not important.

The entire region around the AV3V is the part of the brain where the osmometric and volumetric signs are interpreted and thus control drinking. As a matter of fact, the AV3V seems to receive data that can actually stimulate volumetric thirst. And the baroreceptors that are in the atria of the heart... the sensory data they receive is sent to a nucleus in the medulla. We call this nucleus, "the nucleus of the solitary tract." From this nucleus, exons are sent all over the brain.

The second signal is provided by the peptide, angiotensin. Angiotensin (a hormone is a peptide) is another example of a chemical being unable to penetrate the blood-brain barrier. Thus, the only neutrons this hormone can affect are located within the circumventricular organs. Because these organs are located on WHICH SIDE OF THE BARRIER?

Further study has told us that the subfornical organ (SFO), which is also a circumventricular organ, is the location where angiotensin actually acts first to produce volumetric thirst. It is located BELOW the ventral fornix (not necessary to know, but if ya were curious...)



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