median aperture of fourth ventricle

(redirected from arachnoid foramen)

me·di·an ap·er·ture of fourth ven·tri·cle

[TA]
the large midline opening in the posterior inferior part of the roof of the fourth ventricle, connecting the ventricle with the posterior cerebellomedullary cistern (cisterna magna).

me·di·an ap·er·ture of fourth ven·tri·cle

(mē-dē'ăn ap'ĕr-chŭr fōrth ven'tri-kĕl) [TA]
The large midline opening in the posterior inferior part of the roof of the fourth ventricle, connecting the ventricle with the posterior cerebellomedullary cistern.
Synonym(s): apertura mediana ventriculi quarti [TA] .