Lateral view into the lateral recess of the fourth ventricle. In this dissection, the choroid plexus and tela choroidea of the fourth ventricle are reflected to reveal the dorsal cochlear nucleus on the lateral edge of the floor of the fourth ventricle along with the foramen of Luschka. Both of these structures lie within the lateral recess of the fourth ventricle. The roof of the fourth ventricle is comprised of a thin sheet of white matter called the superior medullary velum, which stretches between the superior cerebellar peduncles. The tela choroidea and inferior medullary velum comprise the inferior portion of the posterior fourth ventricle. (Image courtesy of AL Rhoton, Jr.)