Tela choroidea of third ventricle

Tela choroidea of third ventricle is a double fold of vascular pia mater located in the roof of the third ventricle. It infringes into the cavity of third ventricle from the roof, forming choroid plexuses hanging into the cavity on both sides of the midline. These choroid plexuses are responsible for producing cerebrospinal fluid.

Importantly, the same tela choroidea on the roof of the third ventricle extends laterally through the choroid fissure and passes through the interventricular foramen of Monroe. By doing so, it enters the lateral ventricles on both sides and forms the choroid plexus of the lateral ventricles.

The arterial supply to the vascular core of the tela choroidea of third ventricle (as well as the lateral ventricle) is provided by the anterior and posterior choroidal branches of the internal carotid and posterior cerebral arteries.