title: Osmotic homeostasis.
abstract: Alterations in water homeostasis can disturb cell size and function. Although most cells can internally regulate cell volume in response to osmolar stress, neurons are particularly at risk given a combination of complex cell function and space restriction within the calvarium. Thus, regulating water balance is fundamental to survival. Through specialized neuronal "osmoreceptors" that sense changes in plasma osmolality, vasopressin release and thirst are titrated in order to achieve water balance. Fine-tuning of water absorption occurs along the collecting duct, and depends on unique structural modifications of renal tubular epithelium that confer a wide range of water permeability. In this article, we review the mechanisms that ensure water homeostasis as well as the fundamentals of disorders of water balance.
authors: Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts jdanzige@bidmc.harvard.edu.
authors: John
authors: J
authors: Danziger
authors: Department of Medicine, Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors: Mark L
authors: ML
authors: Zeidel
mesh_terms: D001921:Brain / Q000166:cytology*; D048429:Cell Size; D003919:Diabetes Insipidus / Q000503:physiopathology; D006706:Homeostasis / Q000502:physiology*; D006801:Humans; D007010:Hyponatremia / Q000503:physiopathology; D007679:Kidney Medulla / Q000502:physiology*; D007685:Kidney Tubules, Collecting / Q000502:physiology; D009997:Osmotic Pressure; D011984:Sensory Receptor Cells; D013894:Thirst / Q000502:physiology; D014667:Vasopressins / Q000502:physiology; D014867:Water / Q000502:physiology*; D014882:Water-Electrolyte Balance / Q000502:physiology*
chemical_list: D014867:Water; D014667:Vasopressins
keywords: hypernatremia; hyponatremia; renal physiology; water-electrolyte balance