Introduction to Nervous Tissue

In this video, we're going to begin our introduction to the fourth primary type of tissue found in the human body, which is nervous tissue. Now, before we continue, it's important to note that in this particular section of our course, we're only going to briefly introduce the basics of nervous tissue. But later in our course, in a different chapter, we're going to cover nervous tissue in a lot more detail. And so the advanced material on nervous tissue will be covered later in our course. And so that being said, let's get started with some of the basics of nervous tissue. And so nervous tissue can be defined as tissue that is specialized to generate and carry electrical impulses throughout the body. And these electrical impulses are commonly referred to as action potentials. Now, in terms of where nervous tissue can be located in the body, we can say that it's going to be found in the brain, in the spinal cord. And it's going to include nerves that extend throughout pretty much the entire body. And so if we take a look at our image down below, notice here, we're showing you a figure of the human body. And we're indicating where the nervous tissue can be found. And so, of course, the nervous tissue can be found in the brain. And it can also be found in the spinal cord, which is going to extend from the brain down through the torso as you see here. And then of course, the nervous tissue is going to include nerves that extend pretty much throughout the entire body. And so you can see the nerves extending throughout different regions of the body as you see here. And so really the nervous tissue is going to be composed of two main types of cells. The first main type of cells are going to be the neurons. And the second main type of cells are going to be the neuroglia or the glial cells. Now, the neurons are going to be the primary type of cell or the nervous tissue and they are going to be responsible for generating and conducting electrical impulses. Now, the neuroglia or the glial cells on the other hand, do not conduct electrical impulses and therefore, they are nonconducting cells. And so instead of conducting electrical impulses, these neuroglia or glial cells are going to be cells that support insulate and protect the delicate neurons that conduct electrical signals. Now, it's also noteworthy that the term neuroglia or glial cells actually encompasses multiple different cell types. So it's not just one unique type of cell that these neuroglia or glial cells are referring to. And So let's take a look at our image down below over here on the right hand side. And what you'll notice is that we're showing you the two primary types of cells of nervous tissue. And again, uh the main cell is going to be the neurons which are going to generate and conduct electrical impulses. And we'll talk more about the structure of the neurons and our next lesson video. But what you'll notice here is that the neurons are going to have these long tails and they're going to be here in these positions. Here's another neuron and it's got this long tail once again. And what you'll also notice is that there are some glial cells that are being labeled here uh with these arrows. And so we can go ahead and put glial cells here in this blank. And what you'll notice once again about the glial cells is that the term encompasses multiple cell types. And so uh to represent that, notice that we've got a bunch of different types of glial cells here. We've got these red glial cells, we've got some blue ones over here. And then we've also got some greenish glial cells as well. And again, these glial cells are going to be important for supporting insulating and protecting the delicate neurons. And so this year concludes our brief introduction to nervous tissue and we'll be able to learn some more and apply these concepts in practice as we move forward So I'll see you all in our next video.

If a sensory nerve running from the hand to the spinal cord is severed, you will lose feeling in your hand. What statement best describes the reason for this?

• A. The electrical impulse can no longer be conducted from the hand to the spinal cord.
• B. The neurotransmitter molecules can no longer travel from the hand to the spinal cord.
• C. The neuron can no longer transmit the signal from neuron in the hand to the neuroglial cells in the spinal cord.
• D. The neuroglia cells can no longer transmit the signal from the hand to the spinal cord.

Which of the following is NOT a function of neuroglia?

• A. Protecting neurons.
• B. Supplying nutrients to neurons.
• C. Regulating the composition of interstitial fluid.
• D. Conducting electrical impulses.