The interventricular foramen are the orifices of communication between the lateral ventricles and the third ventricle. Each foramen is bound in front by the corresponding anterior crus of the fornix, behind by the thalamus and choroid plexus, above by the anterior crus of the fornix, and below by the ependyma reflected form the thalamus to the anterior crus of the fornix. The two foramina have a common orifice in the third ventricle. This forms a y-shaped passage called the foramen commune anterius. Through this passage cerebrospinal fluid in one lateral ventricle may enter the other lateral ventricle.

Foramen interventriculare

Foramen interventriculaire