Connective Tissues Types (Nursing)

00:00 So now let's discuss the different types of connective tissue. There are 2 major types. We have mature connective tissue as well as embryonic connective tissue. Of the mature connective tissue, we have loose connective tissue, dense connective tissue, cartilage tissue, bone tissue also known as osseous tissue, and then the blood. So first let's start with loose connective tissue. Loose connective tissue can be further subdivided into 3 different subtypes.

00:35 There is areolar connective tissue, adipose tissue, and reticular connective tissue. Of the 3, areolar connective tissue is the most widely distributed. It contains all 3 fibers as well as many different cell types. Also, it contains a semi-fluid ground substance that contains GAGs or glycosaminoglycans such as hyaluronic acid and chondroitin sulfate. The 2nd type, adipose tissue, is going to contain a large number of adipocytes but has very few fibers and ground substance. This is usually closely associated with all areolar connective tissue and also is found in the fatty tissues throughout the body. The 3rd type, reticular connective tissue, is going to contain reticular fibers as well as reticular cells and a little bit of ground substance.

01:36 The 2nd type of mature connective tissue is the dense connective tissue. Dense connective tissue can also be subdivided into 3 different types of tissue. You have dense regular tissue, dense irregular tissue, and elastic tissue. The dense regular tissue is mainly made up of collagen fibers that are arranged in bundles and is going to have the fibroblast cells arranged in between these bundles of collagen fibers. The dense irregular also has collagen fibers but these are not as nicely arranged as what you find in the dense regular. The last one, elastic tissue, is going to contain elastic fibers as well as fibroblast. This is going to be found in parts of the body that need to be able to stretch such as the lung tissue so that you may breathe. Another type of mature connective tissue is cartilage. Cartilage tissue can be further subdivided into 3 different types of cartilage. The most abundant of which is hyaline cartilage.

02:46 You have hyaline cartilage, fibrocartilage, and elastic cartilage. Of these 3, hyaline cartilage is the most abundant in the body. It is made up of mainly collagen fibers that are arranged in bundles with chondrocytes which translates to cartilage cells found in a gelatinous ground substance. This is usually found at the articulations or the joints between bones. The 2nd type of cartilage tissue is fibrocartilage. This is going to be made up of collagen fibers and thick bundles as well as chondrocytes and a gelatinous ground substance as well. This is a little different than the hyaline cartilage in that it is much stronger because of its arrangement. This can be found in the disc between each of your vertebrae in the spine. The 3rd type of cartilage is elastic cartilage. This is made up of elastic fibers instead of collagen as well as chondrocytes found in a ground substance. An example of a place on your body where you would find elastic cartilage is the outside part of your ear or the auricle. The next type of mature connective tissue that we'll talk about is the blood. Now a lot of times when people think of the blood, they don't think of it as a tissue but it is in fact a type of tissue. Now the blood does not contain any fibers but it does contain cells and extracellular matrix. Specifically, it contains red blood cells, white blood cells, and platelets which are like pieces of red blood cells. As well, the ground substance is a liquid known as plasma which the red blood cells, white blood cells, and platelets are suspended in. Finally, we have bone tissue. This is the last of the mature connective tissues. Bone tissue is also one of those ones that most people do not normally think of as a tissue and that's because usually when we think of tissue we think of things that are soft, but remember ground substance can be solid and in this case that's what we have of bone tissue. The fibers down in both tissue include collagen and the cells are referred to as osteocytes, which translates to bone cells. In this case, the ground substance is a calcified matrix that gives the bone tissue its sturdiness or its hardness. Outside of mature connective tissue, we also have embryonic connective tissue. This type of connective tissue is found in the embryo and is used during development. There are 2 main types of tissue found in embryonic connective tissue. You have the mesenchyme as well as the mucous connective tissue. The mesenchyme is made up of mesenchymal cells as well as reticular fibers all suspended in a semi-fluid ground substance. The mucous connective tissue of embryonic tissue is going to contain fibroblast as well as collagen and a more jelly-like ground substance.

06:04 This can be found in the umbilical cord of the embryo. Pop quiz. What type of tissue is displayed here? And how do you know? The answer is this is a connective tissue and specifically this is a loose connective tissue. And if you want to get even more specific, this is areolar connective tissue. How do I know this? First, when looking at this image, you notice that the cells are widely distributed throughout the image and instead of being closely packed on top of each other. As well, you notice the presence of different types of fibers. So this gives you a clue that we are talking about connective tissue as connective tissue involves these 3 different components whereas epithelial tissue is tightly packed cells. The 2nd clue that it is loose connective tissue is the arrangement of the fibers that you see. And finally, we know it is areolar connective tissue because you can see the presence of multiple different types of fibers in the image.