Okay, this is the first presentation in the skeletal system. And the skeletal system is my favorite part of anatomy. My background is in biological anthropology and forensic anthropology. And I spend hours and hours looking at bones, and what they can tell us. One of the main things that we would look at is a biological profile, and you can determine age, sex, ancestry, stature, pathology, trauma. Everything from bone. So we're going to are going to spend quite a bit of time on this, because really understanding the bones and where they are located will really give you an indication of the other organs, where they're located. A lot of times, arterial supply is named after the bones that they are in close proximity to. So we're going to introduce the concept of the skeletal system. We'll talk a little bit about the tissue and bone development. Then we'll talk about the actual, discrete bones and some of the landmarks on them. So when we talk about bone, the main thing that I want to get across is that it is a dynamic organ. And what I mean by that is, that it changes throughout life. Yes bone will stop growing in terms of length, but it will constantly be changing as you go through life. Either adding bone as you move muscles, or actually loosing bone in the case of certain pathology such as osteoporosis. Now, when we talk about the entirety of the skeletal system, we're talking about more than just bone. But when you think about bone, typically we're thinking about osseous tissue. And that is the hard stuff, okay. So the bone actually will harden through organic materials, as well as minerals. And so when we think of the dry bone that you typically think of when you think of a skeleton, you're thinking of the osseous tissue. So we'll talk a lot more about what that actually is composed of. Importantly also, part of the skeletal system is articular cartilage. And you'll find articular cartilage wherever you have a joint. And when I talk about joints, that's where two bones meet up together. So very important in terms of shock absorption, and allowing for ease of movement at these joints. Additionally, you're going to have dense connective tissue. So you'll see me abbreviating CT quite a bit. That just means connective tissue. Now this dense irregular or dense regular connective tissue you'll find in certain areas, particularly in terms of the periosteum. And this is just a layer that surrounds all the bone except for in the articular cartilage region that's really providing additional protection. It's also an important area where you're going to have cells differentiating to allow for bone growth. Also, connective tissue will connect to the bone. So when we're talking about ligaments and tendons, those are going to be a type of density regular connective tissue. You'll also have epithelial tissue. This is particularly important in terms of paranasal sinuses. So if you think of my sinuses are acting up, it's typically an inflammation of this epithelial tissue. And we'll talk about that a lot more when we talk about the skull. Lastly, I want to talk about adipose tissue and the neurovasculature. Anytime I use the term neovasculature, that's going to mean nerve, artery, and vein. So nerves are important in terms of communicating with your central nervous system, so your brain and your spinal cord. Artery is what's bringing the supply to bones, so blood supply. And then veins are going to drain the blood, so returning to the heart. And in terms of adipose tissue, if you look at this frontal section of the bone, you'll have what's referred to as the marrow cavity or the medullary cavity. And within that, in a living individual, you can have that yellow fat marrow. That's very important in terms of energy storage. So that's just a quick introduction. Key here is that we're talking about a dynamic structure. It changes throughout life. So not static like the dry bone that we typically think of. So we're going to continue this discussion in terms of the functions, not only of the bone, but of the entirety of the skeletal system.