In this video, we're going to talk about the second type of loose connective tissue in our lesson, which is reticular connective tissue. And so recall from our previous lesson videos that one of the 3 protein fibers that can be found in the extracellular matrix are reticular protein fibers. And so it's no surprise that reticular connective tissue is only going to have those reticular protein fibers in its extracellular matrix, which is why reticular connective tissue is called reticular. And, also, this is why the fibroblasts of reticular connective tissue are actually called reticular cells. Because, again, these reticular cells only produce those reticular protein fibers in the extracellular matrix.
Now because there are only reticular fibers in the extracellular matrix of reticular connective tissue, what this means is that the other two types of protein fibers, including collagen fibers and elastic fibers, are not found in their extracellular matrix, which means that the extracellular matrix of reticular connective tissue is going to have a lack of structural diversity. And that lack of structural diversity is going to lead to a lack of functional diversity in reticular connective tissue as well. Now recall that the term reticular is actually a term that means netlike. And so this reminds us that those reticular protein fibers are going to have those collagen proteins arranged in a netlike or a branched structure. And that branch structure actually allows it to resist forces in multiple directions, which is really important for being able to provide structural support.
And so reticular connective tissue is going to be important for providing structural support by, again, using its branched reticular protein fibers in its extracellular matrix. Now, in addition to the reticular cells and reticular connective tissue, there can also be a host of other migratory immune cells in reticular connective tissue as well. Now, in terms of the functions of reticular connective tissue, here in this video, we're only going to focus on one main function of reticular connective tissue, and that is going to be that reticular connective tissue forms the internal scaffolding for soft organs, such as, for example, the lymph nodes, the spleen, the liver, the kidneys, the thymus, and the bone marrow, for example. And so because reticular connective tissue does form the internal scaffolding providing structural support in these soft organs, it means that reticular connective tissue is going to support the functions of each of these soft organs. For example, reticular connective tissue with its branched reticular fibers can actually be used to filter dead blood cells in the spleen, and it can also be used to filter microbes in the lymph nodes, for example.
And in the bone marrow, reticular connective tissue is going to provide the structural framework for hematopoiesis to occur, which is actually the process of blood formation, which again occurs in the bone marrow. And so, again, what we're saying here is that reticular connective tissue, because it provides that structural support and that internal scaffolding framework inside of these soft organs, it's going to support the functions of each of these organs. And so notice over here on the right, we're showing you an image of a person and you can see the lymphatic vessels going through this person here. And each of these bulges that you can see throughout the lymphatic vessels represent lymph nodes. And again, we know that reticular connective tissue is going to form the internal structural framework of these lymph nodes as well as the bone marrow, and the bone marrow is found inside of the bones as you can see in this little image.
It's also going to form the internal structural framework of the kidneys, of the spleen, the liver, and the thymus as well. And so notice here we have a micrograph that's showing you reticular connective tissue where you can see all of these reticular cells. And in some micrographs, you're actually able to see the reticular fibers that are branching through the extracellular matrix. With the proper staining for a certain, you can see them. And in this particular micrograph, they're a little bit harder to see, but they can be seen.
And so this here concludes our lesson on reticular connective tissue. And as we move forward in our course, we'll be able to apply these concepts and learn more about other types of loose connective tissue. So I'll see you all in our next video.