Hi. In this lesson, we'll be talking about the cells that compose the nervous system or neurons. Now the nervous system is a network of nerve cells, or neurons, that transmit signals throughout the body. The neuron is the major cell of the nervous system and it will both send and receive electrical and chemical signals, we'll get into more about that in a little bit. But neurons aren't the only important cells of the nervous system, we also have these cells called glia or glial cells, and these are going to serve to both support and protect neurons. However, their role is not very well understood yet. It's clear that they do certain things, but it's also clear that they're doing a lot of behind-the-scenes stuff that we haven't quite grasped yet.
So here you can see a neuron, and we'll talk about its anatomy in just a little bit, and this is a glial cell. Technically, this is actually known as an astrocyte, and that actually comes from its almost star-like appearance with all these appendages going out in every which way. Now, the nervous system can actually be broken down into two components: the central nervous system and the peripheral nervous system. The central nervous system is the brain and the spine, and the peripheral nervous system is basically everything else.
So here you can see we have our central nervous system, and I'm going to just kind of outline it in blue. Here is our spine, the brain, and that is our central nervous system. Now, all of these other nerves you see projecting from the spine that's all part of the peripheral nervous system. And with that, let's actually go ahead and flip the page.