Development of the Central Nervous System Practice Test 2026 - Free CNS Practice Questions and Study Guide

The tela choroidea is a well-vascularized layer of pia mater that forms the vascular framework over the choroid plexus inside the ventricles. It consists of pia mater with a rich network of blood vessels that support the choroid plexus epithelium, which produces cerebrospinal fluid. This structure is distinct from the arachnoid layer and from the ependymal lining of the ventricles. The choroid plexus itself sits on this vascular pia, with fenestrated capillaries supplying the plasma, while the barrier properties of CSF are provided by the tightly connected ependymal cells.