Analogy

A body affected with Multiple Sclerosis is like a city (Melbourne) with Metro as their primary public transport company (trains). The people of the city are the signals (action potential/ signalling molecules) sent throughout the body. The railways are like the neurons allowing rapid transmission of signals (they are made of metal and can conduct electricity very well). The trains are the myelin sheath covering the axons. The damaged myelin sheathes from people with MS are like the trains with problems cause by metro. Damaged myelin sheath means problems with getting the signal around. Of course there are other pathways of communication within the body, such as the endocrine system, which are like the buses and trams of our analogy, but the fastest way of communication (moving people around a city) is by train. Metro being in charge of our railway system can be associated with a body being affected with Multiple Sclerosis because of their "unpredictable" behavior. Sometimes, the trains are running on time, (the person's nervous system functions properly) and sometimes, the trains are late (the person may show a wide spectrum of signs and symptoms). The efficiency of signal transmission varies, but most of the time, we get delays (as Metro lives up to it's name).
Picture
An image of a damaged myelin sheath