| Lateral recess of fourth ventricle
The narrow recess of the ventricle that extends laterally over, and down along the side of, the inferior cerebellar peduncle and the overlying cochlear nuclei; at its tip it opens by way of the Luschka foramen into the cistern at the cerebellopontine angle (lateral cerebellomedullary cistern), this being a portion of the subarachnoid space. By way of this recess, part of the choroid plexus of the fourth ventricle protrudes into the subarachnoid space. | |