subfornical organ

physiology

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July 14, 2026

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The subfornical organ is a circumventricular organ located in the dorsal part of the third ventricle of the brain. It is a specialized area that is sensitive to hormones like angiotensin II and signals changes needed for regulating salt and water balance. This organ plays a role in thirst and drinking behavior, with osmoreceptors within it detecting increased concentration of dissolved substances in extracellular fluid, indicating cellular dehydration and triggering the sensation of thirst. The subfornical organ also projects directly to vasopressin-producing hypothalamic neurons.12

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human nervous system
Vasopressin and cardiovascular regulation
Another circumventricular organ, called the subfornical organ, lies in the dorsal part of the third ventricle; it is particularly sensitive to hormones such as angiotensin II and signals that changes are needed for the regulation of salt and water balance. Both regions project directly to vasopressin-producing hypothalamic neurons. The area…
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Another circumventricular organ, called the subfornical organ, lies in the dorsal part of the third ventricle; it is particularly sensitive to hormones such as angiotensin II and signals that changes are needed for the regulation of salt and water balance. Both regions project directly to vasopressin-producing hypothalamic neurons. The area…
Read More