I've been waiting for a while to take on another multi-part project (ok, I needed to recover from EB first), and now I think it is TIME. Time for a series SO LARGE that it's going to take me probably more than three weeks, or even four to finish (with breaks for Friday Weird Science, hey, I know what you're really here for). This is going to be INTENSE.
Today I would like to introduce you to the CRANIAL NERVES. When many people think of nerves, they tend to think of white, ropey kind of things which go down your hand. You know, like this:
The nerves that we tend to think of are bundles of neurons which extend from the central nervous system to provide impulses to, and receives sensory information from, various areas of our body. Most people think that these nerves extend exclusively from the spinal cord, and that all the impulses that you need travel up and down via the spinal cord. And these nerves certainly exist and you couldn't do a whole lot without them. But what a lot of people don't know is that a large portion of your body is innervated DIRECT from your brain, with nerves that we call the cranial nerves (because they emerge from, you know, the cranium). There are twelve of these cranial nerves, and over the next several weeks, you all will be getting a crash course in neuroanatomy as I go through them in detail, where they come from, where they go, what they are generally responsible for, and what happens when they are not working properly.
You can see the twelve cranial nerves listed in the photo above. Numbered 1-12, grad students in neuroscience and medical students in anatomy have to remember them all, as well as their characteristics (luckily for you, there will be no quiz at the end of this lesson!). To help in these we've contrived various mnemonics over the years. My favorites (the ones that aren't horribly dirty) are below.
Continue Reading »