DRUG DESCRIPTION. NAMENDA XR is an orally active NMDA receptor antagonist. The chemical name for memantine hydrochloride is 1-amino-3,5-dimethyladamantane hydrochloride with the following structural formula: The molecular formula is C12H21Nâ¢HCl and the molecular weight is 215.76.
There are three main parts to the ear, including the inner ear, middle ear and outer ear. In order for hearing to occur, there is a sequence of actions that must occur to transform waves of sound in the air into electrical impulses. These impulses are transmitted to the brain by the auditory (hearing) nerve.
The middle and inner parts of the ear are located in hollow spaces on either side of the head within the temporal bones of the skull. To hear sound, the ear has to do three basic things: 1  Direct the sound waves into the hearing part of the ear. 2  Sense the fluctuations in air pressure. 3  Translate these fluctuations into an electrical signal that the brain can understand.