osmoreceptor
Specialized neurons that detect changes in blood osmolality and trigger appropriate neuroendocrine responses to maintain water balance.
Full Definition
Osmoreceptors are specialized sensory neurons primarily located in the hypothalamus that monitor changes in plasma osmolality and blood volume to maintain homeostatic water balance. These cells detect increases in osmolality through mechanosensitive ion channels that respond to cell shrinkage caused by water loss. When activated, osmoreceptors stimulate the release of antidiuretic hormone (vasopressin) and trigger thirst responses. Key populations are found in the organum vasculosum of the lamina terminalis (OVLT) and subfornical organ, areas that lack a complete blood-brain barrier.
Usage
Usage note: Distinguish from volume receptors and other mechanosensitive cells in clinical contexts.
In Context
- "The patient's osmoreceptors failed to respond appropriately to increased plasma osmolality." — Clinical case report
- "Osmoreceptor sensitivity decreases with aging, contributing to impaired water balance in elderly patients." — Geriatric medicine review