[MUSIC] So in this module we're going to meet the stars of the nervous system, and the stars of the nervous system are neurons. Neurons are really special. So, admittedly, I am a complete neuro-chauvinist. But, I can tell you that, let's say you've seen ten gastrointestinal cells, you've seen em all. Let's say you've seen ten cardiomyocytes, you've seen em all. Ten lung cells, liver cells, kidney cells, etc. Kind of pretty standard. There might five, ten different types but after that you're, you're out of variation. Totally different story in the, in the department of neurons. So, neurons are, are basically unique. You could ca-, if you were a real lumper, you could categorize them into maybe a few million different types. So, we are going to look at neurons in some detail. Before, before we get into their particular appearance, let's just understand one of the features that makes neurons so unique. And that is that they are the longest, they can be the longest cell in the body. So, our longest neuron is a neuron that has a process that starts at your big toe and ends right here. In me, that's about five feet, one and a half meters. In really tall people that can be six feet, two meters. So, that's a really long process. There's no other ce, cell type in the entire body that is that long or that large. Now, in the next segment, what we're going to do is we're going to get the vocabulary to understand the, the individual uniqueness of of neurons. [MUSIC].