In this video, we're going to begin our lesson on eukaryotic cilia and flagella. The cytoskeleton, specifically microtubules, is a major structural component of both cilia and flagella. Both are important for providing cell movement. They also extend outwards from the cell surface and are anchored to the cell by a basal body. Cilia are short, hair-like structures covering the cell, while flagella are longer, tail-like structures that can be distributed in different ways. Both cilia and flagella are made up of long microtubules that are together in a 9+2 arrangement. This 9+2 arrangement refers to the fact that there are nine pairs of microtubules surrounding two central microtubules.
Notice in the image on the left-hand side, we are showing cilia, which are these short hair-like projections sticking off the surface of the cell. We're also showing flagella, which are longer tail-like structures. You can see, zooming into the structure, a 9+2 arrangement, which again refers to the fact that there are nine pairs of microtubules surrounding two central microtubules. These microtubules project throughout the entire structure, downwards, as seen in a bird's eye view at the very top of the cilia or flagella. This concludes our brief introduction to eukaryotic cilia and flagella, and we'll get some practice applying these concepts as we move forward. I'll see you all in our next video.
