The term circumventricular organs refers to accumulations of highly-vascularized, functionally specialized tissues distributed principally along the midline of the ventricular system from the forebrain to the hindbrain. They include the subfornical organ, the organum vasculosum, the median eminence, the neurohypophysis, the pineal gland, the subcommissural organ and the area postrema. Some authors include the choroid plexus ( Carpenter-1983, McKinley-1990 ). They are commonly classified as either humerosensory system or secretory circumventricular organs ( Duvernoy-2007 ). Updated 17 Aug 2024.