In this video, we're going to talk about the 4th commonly recognized characteristic of epithelial tissue, which is that epithelial tissue is supported by connective tissue. Recall that connective tissue is one of the four primary types of tissue found in the human body. Later in our course, we're going to talk more about connective tissue. But for now, what we're saying is that epithelial tissue is supported by connective tissue. Recall that the epithelial tissue is avascular, which means that it does not have any blood vessels.
This is what allows connective tissue to support the epithelial tissue, because the connective tissue that is underneath the epithelial tissue is going to be vascular, which means that it does contain blood vessels. The vascular connective tissue with blood vessels is going to support the epithelial tissue by supplying nutrients to the epithelia and helping to remove wastes as well. The nutrients that can be supplied through the blood vessels of the connective tissue include substances such as glucose and oxygen. The removal of waste could include removing carbon dioxide gas, for example. If we take a look at our diagram up above here, notice once again that the epithelial tissue is avascular but innervated with nerves.
Because it is avascular, this allows for the vascular connective tissue that's underneath to support the epithelial tissue. Notice that the connective tissue here is going to be vascular in nature because it does have blood vessels, and it's also going to be innervated with nerves. Again, because the connective tissue is vascular with these blood vessels, it is going to allow for nutrients to diffuse from the blood into the epithelial tissue, supporting that epithelial tissue. This here concludes our 4th commonly recognized characteristic of epithelial tissue, and we'll be able to talk about the 5th and final characteristic in our next video. So I'll see you all there.