two curved openings (shaped like a horseshoe) located deep within the top section of the brain, that provide a pathway for cerebrospinal fluid. Cerebrospinal fluid is the fluid that protects the brain and spine from trauma. There is one lateral ventricle on each side of the brain. In addition to the two lateral ventricles, there is the third ventricle and the fourth ventricle. The two lateral ventricles are the largest of all the ventricles in the brain.