 So there's two pieces of your axial skeleton that are associated with your bony thorax, and that is the sternum, which is this whole, basically your breastbone. It's the sternum. And your ribs. The sternum plus the ribs make up your bony thorax. Your ribs articulate with your thoracic vertebra in the back, on the posterior side. And this is where I wanted to show you a picture so that you could kind of visualize the unique features on the thoracic vertebra. So we know this is a thoracic vertebra, and we know that because, look, there is a rib attached to it. There is a rib articulating with this vertebra. We have two places where the ribs articulate. We have here, that's actually called the tubercle, tubercle of the rib, and we articulate with the body of the vertebra, and that is the head of the rib. So the head of the rib articulates with the body of a thoracic vertebra, and the tubercle of the rib articulates with the transverse process of the thoracic vertebra. The place on the vertebra, where the articulation happens, are you ready for this? Visualize, if you will. The head of the vertebra articulates with the costal demi facet on the body, and there's no eye there, on the body of the thoracic vertebra. Here's my body. Why is it called a demi facet? Demi half, it's half a facet, which makes complete sense because you can't really see it here, but the head of the vertebra articulates with the costal demi facet of two thoracic vertebra. So stack them up. I'm just going to show you so that you can visualize this. You stack them up, and I don't know, can you even see anything? You agree. Now, we have costal demi facets on the body, and if we were to attach a rib right here, the head of the rib would actually attach between the two, like a little bit on the inferior surface of the top vertebra and a little bit on the superior surface of the bottom vertebra. Whoa, did you follow that? And because it's half one rib articulation attaches half to each vertebra, it's called a demi facet, a half a facet. The whole facet is the whole thing. That rib, the head of the rib attaches there, and then the tubercle of the rib attaches to a facet on the transverse process. So, and that's my costal facet. So my costal facet is found here, right here, except I do not want, I need a new color, new colors. It's going to be green. Here is my costal facet. The costal facet on the transverse foramina, I mean the transverse process of the thoracic vertebra, articulates with the tubercle of the rib. The head of the rib articulates with the costal demi facet on the thoracic vertebra, the body of the thoracic vertebra. Whoa, write that down in one little mouthful. The sternum is pretty straightforward. I think we have three sternum parts that we have to know. First of all, is this tiny little bad boy down here. That little twanger is called the manu, I mean the xyphoid process. Here it is, the xyphoid process. It hangs down. It's like palpated if you grab your sternum. This is the body of the sternum. And this guy right here, the top little piece, is called the manubrium. Manubrium. On the manubrium is the suprasternal notch, that little notch right there, and you can feel that puppy. Aw, there's my suprasternal notch. You can even see it if you get your, here we go, sternocleidomastoid, which is this muscle right there, attaches to your suprasternal, attaches next to your suprasternal notch of your manubrium of your sternum. How awesome are bone bumps? The sternal angle is this thing. There was one more. That's my sternal angle. And the sternal angle on, you can actually, I can feel mine. People have a more pronounced sternal angle, but you can feel the, it's a point that you can actually identify. And I think there's clinical significance in that puppy. You identify it and then you know where to stick your, what's that thing that you listen to the heart with. WSF scope. Shall we do the pectoral girdle next? I'm in. Let's do it.