contributes to morphology of fourth ventricle fourth ventricle lateral aperture FMA:78473 lateral aperture BAMS:LA4V UBERON:0003992 foramen of Key-Retzius NCIT:C32625 neuronames:640 One of the two lateral openings of the fourth ventricle into the subarachnoid space at the cerebellopontine angle[MP]. foramen of Luschka MA:0002946 lateral aperture of fourth ventricle Wikipedia:Lateral_aperture BAMS:LAP foramen of Retzius foramen of key and retzius forament of Luschka SCTID:63426007 fourth ventricle aperture