regional part of brain circumventricular organ neuronames:1242 FMA:84081 NLXANAT:20090312 EMAPA:35243 MA:0002942 CVO UBERON:0005408 circumventricular organ circumventricular organ of neuraxis Wikipedia:Circumventricular_organs Any of any of the secretory or sensory organs located in the brain region around or in relation to the ventricular system that are characterized by extensive vasculature and a lack of a normal blood brain barrier (BBB) and allow for the linkage between the central nervous system and peripheral blood flow.