So, now that we've covered functional joint classifications in our last lesson video, in this video we're going to introduce the structural joint classifications, and talk about how those functional joint classifications overlap with these structural joint classifications. And so, there are also 3 structural joint classes and these structural joint classes are based mainly on the binding material that is used between the skeletal elements to join those skeletal elements together in these joints. Now, notice down below we have listed the 3 structural joint classes that are numbered 1, 2, 3. And so, they are the fibrous joints, the cartilaginous joints, and the synovial joints. And so, in the fibrous joints, as their name implies, the skeletal elements are going to be bound by collagen fibers of dense connective tissue.
Which recalls a type of fibrous connective tissue or a type of connective tissue proper. And the type of dense connective tissue that is usually used in these fibrous joints is dense irregular connective tissue. And we'll be able to see that as we move forward in our course and talk more about these fibrous joints. Now, recall from our previous lesson videos that the collagen fibers provide a lot of strength. And so, the strength of these collagen fibers makes fibers joints very stable joints.
But recall that the stability of a joint comes at the cost of the mobility of the joint. And so, fibrous joints have limited mobility and therefore, they are always going to be classified either as synarthroses or amphiarthroses, which are types of functional classifications from our previous lesson videos. And that's why we have the symbol for synarthroses and the symbol for amphiarthroses over here. And so recall that the synarthroses because the symbol does not have a movement arrow going around it, it can remind you that the synarthroses are going to be still or stationary joints that basically allow for no movement and are generally considered immovable joints. And, Amphiarthroses notice the symbol has just one movement arrow going around it.
Which reminds you that they allow for a little or an average amount of movement if you will. And so, both synarthroses and amphiarthroses are going to be limited in their ability, for mobility or movement. Especially in comparison to diarthroses, which allow for dynamic movement. Now, the 2nd joint classification, structural joint classification in our lesson are the cartilaginous joints. And as their name implies, the bones are going to be bound by cartilage.
Either hyaline cartilage or fibrocartilage. But elastic cartilage usually does not have a huge role in these cartilaginous joints. Now, the cartilage in these cartilaginous joints is going to provide stability to the cartilaginous joints. However, once again, the stability of the joint comes at the cost of mobility. And so, like the fibrous joints, these cartilaginous joints are always going to be classified either as synarthroses or amphiarthroses.
Which is why we have the symbols there. Now, the 3rd and final type of Structural Joint Classification in our lesson are the Synovial Joints. And the synovial joints are characterized by having a synovial cavity or a synovial space. Space in between the bones of the synovial joint and ligaments within an articular capsule. And so, later in our course, we're going to talk a lot more about these synovial joints including the synovial cavity, the synovial fluid that they contain, and this articular capsule as well.
But for now, what you should note is that these synovial joints allow for dynamic movement or free range of movement. And so, that means that they are always going to be categorized as diarthroses, which is why we have the symbol for diarthroses here in the lesson. And so, notice that the symbol for diarthroses has multiple movement arrows going around it, which reminds us that diarthroses have, dynamic movement. Now, it is worthy of noting once again that the synovial joints which are categorized as diarthroses can vary in the amount of movement. And so, some synovial joints will allow more movement than other synovial joints.
But again, we'll get to talk more about this as we move forward in our course. For now, let's take a look at our image down below, where we can see a few examples. And so notice over here on the left hand side, we've got the skeleton of this person and we're focusing in on these specific regions. The first region that we're focusing in on is down here on the distal end of the tibia and the fibula of the leg, the lower leg. And so, what you'll notice is over here we have the tibia and here we have the fibula.
And what you'll notice is that, right here in this region on the distal end is a fibrous joint. And we're zooming in here to show you the fibers of this fibrous joint. And again, usually the, fibers of the fibrous joints are going to be of dense irregular connective tissue where the fibers are going to have an irregular or random arrangement of fibers in the extracellular matrix as you can see here. And so, these fibers joints again, they provide a lot of stability, but that comes at the cost of mobility and that's why they're always going to be classified either as synarthroses or amphiarthroses. Now, for the cartilaginous joint, we're focusing in on the spine.
And so, in the spine, there are these intervertebral joints, these intervertebral disks. And in between them are going to be fibrocartilage. And so this is a type of cartilaginous joint. And so, notice zooming in here, we can see the image from our previous lesson videos showing cartilage. And so you can see the chondroblast and the chondrocytes that we talked about from our previous lesson videos on cartilage.
And so, with these cartilaginous joints, again they provide a lot of stability like the fibrous joints can. However, the stability comes at the cost of mobility. And so, like the fibrous joints, they're always classified either as synarthroses or amphiarthroses. And then last but not least, in this person over here we're focusing in on the hip joint. And in the hip joint, that is going to be an example of a synovial joint.
And so, here you can see the femur is coming into contact with the pelvis here at this joint and in this joint, what you'll notice is that there is a synovial cavity, which is this space that you can see right here and it's also going to contain an articular capsule, which is essentially this structure that you can see going around it made of dense irregular connective tissue. And again, we'll be able to talk a lot more about these synovial joints as we move forward in our course. But the synovial joints are usually going to be the joints that most people will think of when you think about joints. So, they include our shoulder joint which has a lot of dynamic movement, our elbow, our knee, our hip joints for example, and there are many others as well. And so, this here concludes our brief lesson on structural joint classifications and as we move forward in our course, we'll be able to learn a lot more about each of these, learn a lot more about each of these types of joints and examples of these types of joints.
And we'll also be able to get some practice applying these concepts. So, I'll see you all in our next video.