The ventricular system in the brain is composed of cerebrospinal fluid (CSF)-filled ventricles and their connecting foramina. CSF is produced by ependymal cells which line the ventricles. They are continuous with the central canal. Ventricles contain around 20% of the total average adult CSF volume, around 20-25 mL.
The ventricular system consists of:
The interconnections between the ventricles occur through the following:
- interventricular foramen (of Monro): lateral to third
- cerebral aqueduct (of Sylvius): third to fourth
- median aperture (of Magendie): fourth to cisterna magna
- two lateral apertures (of Luschka): fourth to cerebellopontine cistern
Major CSF production comes from choroid plexus found in the lateral, third and fourth ventricles of the brain which are highly vascularized epithelial tissue masses . Notably, choroid plexus is not found in the frontal or occipital horns of lateral ventricles, nor in the cerebral aqueduct.
Embryologically, ventricles originate from the central lumen of the neural tube and the cerebral vesicles to which it gives rise.