part_of part of part of fenestrated endothelial cell capillary endothelial cell brain microvascular endothelial cell choroid plexus capillary endothelial cell A capillary endothelial cell that is part of the choroid plexus, characterized by its fenestrated nature with 60 to 80 nm fenestrations and lack of tight junctions. This fenestrated structure allows for the rapid delivery of water and other components, aiding in the production of cerebrospinal fluid (CSF). choroid plexus