The cavities or chambers of the brain are called ventricles. There are 4 ventricles in the brain. namely first, second, third and fourth ventricles.
1. Lateral Ventricles: The 1st and 2nd ventricles of the brain are collectively called the lateral ventricles. There are two cavities inside the cerebral hemispheres. These two cavities are called lateral ventricles. They are individually connected to the 3rd ventricle by the foramen of Monro or interventricular orifice.
2. Third ventricle: The cavity of hypothalamus is called third ventricle. One end of it is connected to the 3rd ventricle.
3. Fourth Ventricle: The cavity of the medulla oblongata is called the fourth ventricle. One end is connected to the cerebral aqueduct and the other end to the central canal of the spinal cord.