Polarization by Use of a Polaroid Filter. The most common method of polarization involves the use of a Polaroid filter. Polaroid filters are made of a special material that is capable of blocking one of the two planes of vibration of an electromagnetic wave.
The lateral ventricles are part of the ventricular system of the brain. Both cerebral hemispheres contain a lateral ventricle. The lateral ventricles are the largest of the ventricles.
In front, the third ventricle communicates with the lateral ventricles, and in back it communicates with the aqueduct of the midbrain (the aqueduct of Sylvius). The fourth ventricle is the most inferior of the four ventricles of the brain. It extends from the aqueduct of the midbrain to the central canal of the upper end of the spinal cord, with which it communicates by the two foramina (openings) of Luschka and the foramen of Magendie.