| Tela choroidea | |
|---|---|
 Tela choroidea andchoroid plexus | |
| Anatomical terms of neuroanatomy |
Thetela choroidea (ortela chorioidea) is a region ofmeningealpia mater that adheres to the underlyingependyma, and gives rise to thechoroid plexus in each of thebrain’sfour ventricles.[1][2]Tela is Latin forwoven and is used to describe a web-like membrane or layer.[3] The tela choroidea is a very thin part of the loose connective tissue of pia mater overlying and closely adhering to the ependyma.[2][1] It has a rich blood supply. The ependyma andvascular pia mater – the tela choroidea, form regions of minute projections known as a choroid plexus that projects into each ventricle.[1][2] The choroid plexus produces most of thecerebrospinal fluid of thecentral nervous system that circulates through the ventricles of the brain, thecentral canal of thespinal cord, and thesubarachnoid space.[4][2] The tela choroidea in the ventricles forms from different parts of theroof plate in thedevelopment of the embryo.[2][1]
In thelateral ventricles, the tela choroidea–a double-layered fold ofpia mater andependyma, produces thechoroid fissure (sometimes also called the choroidal fissure but this is different from thechoroidal fissure of the optic stalk). The choroid fissure is C-shaped, runs between thefornix and thethalamus in the body of the ventricle, and between thestria terminalis andhippocampal fimbria in theinferior horn, and is the location of the attachment of the margins of thechoroid plexus.[5][6] In the choroid fissure of the lateral ventricles, the tela choroidea is a lateral extension of the tela choroidea from thethird ventricle.[7]
In thethird ventricle, the tela choroidea forms the roof of the ventricle. Two vascular fringes from the lower fold invaginate the roof and form the choroid plexus.[7]
The tela choroidea of the fourth ventricle (also known as thetriangular lamella)[8] is a double layer of pia mater and ependyma, between thecerebellum and the lower part of the roof of the fourth ventricle. The two layers are continuous with each other in front, and are mostly adherent throughout. The anterior layer of the fold, contains vascular fringes which make up the choroid plexus.[7] The anterior layer is continuous inferiorly with the pia mater on theinferior cerebellar peduncles and the closed part of themedulla oblongata. Theposterior layer covers the antero-inferior surface of the cerebellum.
Cilia on theependymal cells move to circulate the cerebrospinal fluid. These cilia are unusually multipleprimary cilia.[9]
The blood supply of these plexuses is from theposterior inferior cerebellar artery.The lateral ventricles also contains the right and leftinternal cerebral veins (which drain the choroid plexuses) at its roof (the two veins unite to form the great cerebral vein).[citation needed]
The arteries carrying blood into the choroid plexuses are:[citation needed]
Medial posterior choroidal branches run forward beneath the splenium of the corpus callosum, and supply the tela chorioidea of the third ventricle and the choroid plexus.