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 Ear is the portion of the ear internal to the eardrum, and external to the oval window of the inner ear.Also mammalian middle ear contains three ossicles, which transfers the vibrations of the eardrum into waves in the fluid and membranes of the inner ear.he ossicles directly couple sound energy from the ear drum to the oval window of the cochlea. While the stapes is present in all tetrapods, the malleus and incus evolved from lower and upper jaw bones present in reptiles. See Evolution of mammalian auditory ossicles.