Posts Tagged ‘Nerve Impulse’
Multiple Sclerosis
Wednesday, August 19th, 2009
DESCRIPTION
Multiple sclerosis (MS) is a syndrome of chronic nerve disturbances due to a process called demyelination, a gradual loss of the myelin sheath surrounding each nerve cell. The myelin sheath plays an essential role in transmission of the nerve impulse. Without the myelin sheath, nerve transmission cannot occur, so nerve function is lost. Symptoms correspond to this loss of function in the affected nerves.
Incidence of MS follows a geographic distribution with areas of highest frequency all located in the higher latitudes, in both the northern and southern hemispheres (50–100 cases per 100,000 in higher latitudes versus 5–10 cases per 100,000 in the tropics). High-risk areas include the northern US, Canada, Great Britain, Scandinavia, northern Europe, New Zealand, and Tasmania. (more…)