 Hey everybody, so today we are going to talk about places where bone organs connect together to form an articulation or a joint. The whole lecture is describing the structures of different types of joints, classifying them based on structure, also classifying them based on function, and then we're going to take a look at some of the movements that happen at joints and we're going to take a look at three specific joints. If you think about it, I mean we studied bone organs last time and we learned the names of all the bones and we learned some of the landmarks found, or bumps, found on bones. And we kind of alluded to the fact that, you know what? We learn those bumps because that's where muscles attach to bones. And if you have muscles attaching to your bones, but the attachments, the muscle itself, does not span a joint, then you're going to have no movement at all at that joint. Like you're not going to have it, when that muscle shortens or contracts, you're not going to have any movement happen. It has to shorten or contract around two articulated bones in order to get movement. So this is our bridge between bones and muscles and the rest of our lectures in this session are on muscles. So let's start out looking at the ways that we can classify different, the different functional categories that we can put all our joints that we're going to study into.