 So there are two ways that we can grow our bone and cartilage tissue. And if you think about it, it makes sense that you would have a special type or a way, a mechanism by which growth takes place because we're dealing with a solid, a relatively solid tissue. And so it's a little bit funky. So first of all, we can actually have a process of oppositional growth and this takes place on the surface. So let's just make a little note. This is like on the surface. And interstitial growth is like in the middle. Now here's the deal. Both of these types of growth occur in cartilage and bone. However, they're slightly different. Now, oppositional growth, does it make sense? It takes place on the surface. So basically what happens is at the edge of your tissue, near, let's say, your pericondrium or periosteum, basically you're just going to have cell division take place. And we're going to end up with new cells. And those new cells are going to grow, whether it be chondroblasts or osteoblasts, they're going to barf out more matrix around them. And then the bone is going to increase in diameter or the cartilage is going to increase in diameter. So the growth is going to happen this direction. Can you visualize that? This is increase in diameter. And that happens through oppositional growth. Now, interstitial growth happens in cartilage. It makes complete sense. So the lacuna, you have a cell inside the lacuna and then something triggers, it's time to grow. And so the cell will divide and become two cells. And then the cell, which was an osteocyte, right, because it was just chilling in its lacuna, excuse me, it's a chondrocyte, because this exact form doesn't exactly happen this way in bone. But the chondrocyte is going to go back and become a chondroblast again. So some kind of chemical message gets sent when interstitial growth is going to take place. And now these guys are going to start barfing out their matrix. And basically, they're going to condense the tissue. Like, they're going to squeeze more. They're going to keep their lacuna, but they squish out more matrix around them, so the matrix becomes more dense. Does that, I mean, I could totally visualize that. It's like, if I were in this room and then I wanted to, and the walls were made out of clay, and I wanted to, you know, make more clay, I could totally push more clay into the walls and the walls would become more dense. And the clay analogy isn't fantastic. Something that squishes down becomes dense, like Wonder Bread. So I'm going to squish more Wonder Bread onto my walls, and then, like, they started out being all Wonder Bread-y, but then I can squish more. Like, I could probably fit an entire loaf of Wonder Bread where I had one piece of Wonder Bread, because I could squish it down. That's what your matrix in cartilage is like that. So your matrix just becomes more dense. Your tissue becomes more dense with interstitial growth in the cartilage tissue. Interstitial growth. In compact bone, can you visualize what interstitial growth happened? You can't make bone tissue compact-er. You can't squish it more. It's already solid. However, thank you very much. I would like to say interstitial growth does not happen in bone. Unfortunately, they use the same word for a slightly different process. They say growth at an epiphyseal plate. Bone growth increased length at an epiphyseal plate. They call that interstitial. But think about it for a second. Was the epiphyseal plate? It was hyaline cartilage. That's not bone. So sure, the hyaline cartilage can expand and can create more bone tissue. And we'll look at that whole process in lab today or whenever you come into lab. But that is a different... It's hyaline cartilage that's growing and turning into more bone. However, they refer to it as interstitial bone growth. So, okay, that's cool. Do you have any questions for me? All right. I think that's it, except for our histology preview, which might have to happen in a second.