A small, rounded eminence on each side of the FOURTH VENTRICLE, which receives nerve fibers from the SOLITARY NUCLEUS; SPINAL CORD; and adjacent areas of the MEDULLA OBLONGATA. The area postrema lies outside the BLOOD-BRAIN BARRIER and its functions include acting as an emetic chemoreceptor.

Synonyms: Zone, Chemoreceptor Trigger, Chemoreceptor Trigger Zone, Area Postremas, Trigger Zone, Chemoreceptor, Chemoreceptor Trigger Zones, Area Postrema, Trigger Zones, Chemoreceptor, Zones, Chemoreceptor Trigger, Postrema, Area