Brain ventricles transparent in a brain in external profile view. The ventricles are a collection of cavities. They are located inside the brain. They are continuous with the ependymal duct of the spinal cord. They participate in the secretion and circulation of cerebrospinal fluid (or cerebrospinal fluid). The cerebral ventricles are four in number. They are represented in transparency in bluish gray in this profile view of the brain. The two lateral ventricles are connected to the third ventricle in the center of the brain through the interventricular foramen. Then the structure descends downwards through the midbrain aqueduct. The fourth ventricle is located slightly above and in front of the cerebellum. Then finally, the structure descends into the brainstem. It forms the canal of the spinal cord.