Lateral recess of the fourth ventricle

The lateral recess is a projection of the fourth ventricle which extends into the inferior cerebellar peduncle of the brainstem. The lateral aperture, an opening in each extremity of the lateral recess, provides a conduit for cerebrospinal fluid to flow from the brain's ventricular system into the subarachnoid space.

Ap: area postrema; icp: inferior cerebellar peduncle; lr: lateral recess; ms: median sulcus; scp: superior cerebellar peduncle; sf: superior fovea; sm: Medullary striae of fourth ventricle.