In this video, we're going to talk about the second type of muscle tissue in our lesson which is cardiac muscle tissue. And so cardiac muscle tissue is going to be made of cells that are called cardiomyocytes. And so these cardiomyocytes that make up the cardiac muscle tissue are going to be located in the walls of the heart. And so what's really helpful to note is that the root cardi, which you can see in cardiac muscle tissue and cardiomyocytes is a root that means heart. Now, unlike skeletal muscle tissue which we know is voluntary, cardiac muscle tissue is going to be involuntary, which means that its contractions are not going to be consciously controlled.
And so recall from our last lesson video that skeletal muscle tissue is unique in its voluntary nature. And the other two types of tissue including cardiac muscle tissue and smooth muscle tissue are going to be involuntary in nature, which again means that they are not consciously controlled. We can't just think about the muscle tissue in our heart and cause our heart to increase in pace or decrease in pace voluntarily in a conscious manner. And so, that's what makes it involuntary. Now, cardiac muscle tissue has several other key features that are notable, including the ones that we have listed down below.
And so, like skeletal muscle tissue, cardiac muscle tissue contains striations due to the protein myofilament alignment. And so recall that this means that the cardiac muscle tissue is also going to have a banded or a striated appearance. And so, it turns out that generally, the striations in cardiac muscle tissue are going to be a little bit harder to see than the striations in skeletal muscle tissue. But nevertheless, those striations are still there. Now, another notable feature of cardiac muscle tissue that can make cardiac muscle tissue pretty easily identifiable is that the cardiomyocytes or the cells that make up the cardiac muscle tissue are going to be branching.
And so it contains branching cells or cells that have a branched structure. Now, another notable feature of cardiac muscle tissue is that the cardiomyocytes are going to tend to be uni nucleate. And note that the root uni is a root that means 1. And so, this means that the cardiac muscle cells or the cardiomyocytes, they often are going to have just one single nucleus. And so, recall from our last lesson video, we said that skeletal muscle tissue cells or the muscle fibers can be pretty long, over 1 foot in length in some cases.
And so, because those skeletal muscle fibers can be really long, they certainly need to be multinucleate. However, the heart is a pretty short or a pretty small organ. And so, the cardiomyocytes don't need to be nearly as long as many of those skeletal muscle fibers need to be. And so, one nucleus is generally going to be enough for those relatively shorter cardiomyocytes. Now, the last notable feature of cardiac muscle tissue that we have listed here is that they contain structures known as intercalated discs.
And so these are structures that are going to join the ends of the cardiomyocytes together and enable coordination. And so with these intercalated discs, they are going to help these cardiomyocytes function as a unit, which is going to be critical for the heart to function as a pump and pump blood throughout our entire body. And so let's take a look at this image down below where we can start to piece these things together. And so again, cardiac muscle tissue is going to be found in the heart. And so, notice here we're focusing in on the heart and we've got this micrograph here of cardiac muscle tissue.
Now, the first thing that you should note is that cardiac muscle tissue is going to contain striations like skeletal muscle tissue. Now, those striations might be a little bit more difficult to see, but they are certainly present in the cardiac muscle tissue. Now, the next notable feature that you'll notice here is that it contains branching cells. The cardiomyocytes are branching and so you can see here that we're highlighting some of that branching nature, but you can also see these branches occurring in different areas, different parts here. Now, again, the cardiomyocytes tend to be uni nucleate, which means that they tend to have just one nucleus.
And, that is a tendency. So occasionally, there may be a cardiomyocyte that is multinucleate, but for the most part, every time you see these darkened nuclei, you can assume that is a different cardiomyocyte. And then last but not least here, the intercalated discs are these structures that once again are going to join the ends of the cardiomyocytes together to enable coordination. And so here, you can see that we've identified one of the intercalated discs, but there are more intercalated discs throughout this cardiac muscle tissue. And so, this here concludes our brief lesson on cardiac muscle tissue, and we'll be able to get some practice applying these concepts and talk about the last type of muscle tissue as we move forward in our course.
So, I'll see you all in our next video.