Demyelination is often secondary to an infectious, ischemic, metabolic, or hereditary disorder or to a toxin (eg, alcohol, ethambutol). In primary demyelinating disorders, cause is unknown, but an autoimmune mechanism is suspected because the disorder sometimes follows a viral infection or viral vaccination.
For other uses, see Realm (disambiguation). A realm /ËrÉlm/ is a community or territory over which a sovereign rules; it is commonly used to describe a kingdom or other monarchical or dynastic state. The Old French word reaume, modern French royaume, was the word first adopted in English; the fixed modern spelling does not appear until the beginning of the 17th century.
The realm of our planet comprising of air is known as atmosphere. The realm comprising of water is known as hydrosphere. All living organisms, right from the algae to the plants, the wildlife to human beings, form the biosphere. All land or rocks and ground form the geosphere. Geosphere: Explained! The atmosphere encapsulates the planet. The hydrosphere forms a humongous majority of the surface and also a substantial part of the earthâs crust, including ground water.