I have been recently diagnosed with Bell’s Palsy. The condition is named after the Scottish scientist, Charles Bell, who first described it in 1821. This is an ailment that affects about 200,000 Americans every year and is produced when the facial nerve (a.k.a. seventh cranial nerve) which controls the movement of the muscles on one side of the face becomes inflamed and is unable to function. As you can see in the video below, I have lost the capacity to move the left side of my face.
Most people take movement for granted. We go about our daily activities without giving it much thought. But as I describe in the video, Bell’s Palsy highlights an important principle of physiology. This is that, with a few exceptions (such as in the case of pacemaker cells), the movement of most muscles requires electrical stimulation by signals sent from the brain and conducted by nerves. If there is a problem with the brain centers involved in controlling muscle movement or with the nerves that carry the signals, we become incapable of moving our muscles.
Have you ever wondered what would happen if you shoot a ball from a truck travelling in the opposite direction in such a way that the speed of the truck matches the speed of the ball? That is what the Mythbuster folks did in this video.