Health and medicine
This video describes the structure and function of ependymal cells. By Matt Jensen. Created by Matthew Barry Jensen.
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- So they are ependyma - i.e. (a type of) epithelium (lining). Yet they are glia - i.e. neural cells and therefore nervous tissue? So therefore they are classed as both?
As in, I'm thinking of the four types of tissue: muscle, connective, nervous, epithelium. Yet I'm reading, hearing, they are both? Can they be both/multityped?(7 votes)
- short answer: they are ciliated simple columnar epithelium-like glial cells
long answer: The ependyma is made up of ependymal cells, ependymocytes, a type of glial cell. These cells line the CSF-filled ventricles in the brain and the central canal of the spinal cord. The cells are ciliated simple columnar epithelium-like cells. Their apical surfaces are covered in a layer of cilia, which circulate CSF around the CNS. Their apical surfaces are also covered with microvilli, which absorb CSF. Ependymal cells also produce CSF. Within the ventricles of the brain, a population of modified ependymal cells and capillaries together form a system called the choroid plexus, which produces the CSF.
longer answer: https://en.wikipedia.org/wiki/Ependyma(7 votes)
- What is the purpose of cerebra-spinal fluid?(4 votes)
- and, according to recent research, the cerebro spinal fluid cleans the brains of byproducts while we sleep. (they act like the lymphatic system in the brain)(3 votes)
- Is this the correct pronunciation? I've always heard it like Eh-Peh-DEEE-Moh cells, but if I were to be in a presentation and this word comes up, is there a proper way to say it?(2 votes)
- PoTAYto, potahto, I'm often encountering these discrepencies. In other fields as well, for example with name pronounciation. I wouldn't worry about it. This is classic. How something is pronounced used to indicate your social status and level of culture and/or education. Then it would hint at where a person hails from, but in this multicultural and more egalitarian society, the person to criticize pronounciation could be more at fault. There are exceptions, of course where we grow up reading a word in literature and freak out when its heard spoken for the first time. I find these opportunities for a good laugh! Sorry for the long windedness, big pot of great organic coffee!(2 votes)
- The specialized ependymal cells and capillaries form what?? I can't seem to hear the word he is saying; "toughs?"(1 vote)
- He is saying 'tufts' , as the cells come together to form clumps, or bunches or tufts. He is describing the production of CSF by ependymal cells and capillaries which form the choroid plexus in the brain. I understand why that was confusing! :)(4 votes)
- Since the ependymal cells are leaky and allow the blood to leak into them to give them the fluid volume as said in the end of this video, then wouldn't that be a problem when the CSF goes into the IF of the CNS? Because if the astrocytes' endfeet and the capillaries form the Blood Brain Barrier to regulate the substances into the CNS, it seems like a problem that the same substances kept out by the BBB would go through the ependymal cells into the CSF.(2 votes)
- Where does the cerebrospinal fluid go out? Since additional fluid is being secreted into the ventricles some must also be leaving? Dumped in the blood to get eliminated by the kidneys? If so through what kind of cell?
Thank you(1 vote)
There is some discussion on this question. The CSF fluid goes through the arachnoid villi to the superior venous sinus that connects to the internal jugular vein and goes into the venous blood supply becoming part of the circulatory system. And this is the way out for the majority of the CSF. But there are questions concerning additional ways out of the brain (ears and nose ?). However, since only about 150 cc are in the brain and about 500 cc are made in a day, it does flow out, to make room for more being made in the choroid plexi.(2 votes)
- what are the general difference between body cells from brain cells?(1 vote)
- depends which body cells you are comparing with which brain cells. so ependymal cells and epithelial cells are actually quite similar but you won't really find anything like a neuron in the other 3 types of animal tissue (epithelial, connective and muscular).(2 votes)
- Are epyndymal cells epithelial cells or neuroglial cells?(1 vote)
- The ependyma is made up of ependymal cells, ependymocytes, a type of glial cell. These cells line the CSF-filled ventricles in the brain and the central canal of the spinal cord. The cells are ciliated simple columnar epithelium-like cells.
- At1:55, what are the uses of having additional surface area in the CSF-facing side of the ependyma?(1 vote)
- where is the epithelial columnar located?(1 vote)
In this video, I want to talk about ependymal cells. But to do so, first let me draw the brain and the spinal cord. So I'll just draw a big circle for the brain and I'll draw a long structure like this for the spinal cord. Because there are spaces inside the brain and inside the spinal cord that are full of fluid. And these spaces are connected together. And they are connected to this little skinny canal that goes down the spinal cord. And don't worry about the anatomy of this. We'll go into this in more detail in other videos. But these spaces are full of a kind of fluid called cerebral spinal fluid for the brain and the spinal cord. And the lining of these spaces is called the ependyma, which is made up of ependymal cells. The ependyma is named for a Greek word for covering. And the ependymal cells that make up the ependyma are glial cells of the central nervous system derived from neural stem cells. If we zoom in here and look at some of these ependymal cells, we'll see that they form a simple, cuboidal epithelium. Simple, meaning that they're just one layer of cells; cuboidal, meaning that they're shaped like little cubes; and epithelium, meaning they're a covering, in this case the lining of a cavity. So let's say that this is the side facing the cerebral spinal fluid, which I'll just write as "CSF" for short, for Cerebral Spinal Fluid. And that this side faces the interstitial fluid of the central nervous system, all the fluid between the cells of the brain and the spinal cord. And I'll just write "IF" as short for Interstitial Fluid. On the side of the ependymal cells facing the cerebral spinal fluid are a large number of little tiny processes called microvili, that increase the surface area of the ependymal cells on that side. They also have some processes that are a little longer, called cilia, that are these mobile, whip-like structures that kind of whip around and help move the cerebral spinal fluid around. One of the main functions of ependymal cells is to form a barrier between the cerebral spinal fluid and the interstitial fluid. So to some extent, they limit the movement of cells and large molecules between these fluid-filled spaces and the interstitial fluid of the tissue itself. Now as barriers go, the ependymal cells form a fairly leaky barrier, particularly if we were to compare it to the blood-brain barrier created by the capillaries in the central nervous system and the astrocyte end-feet. And the fact that this is a relatively leaky barrier is actually useful for medical purposes because there are areas where we can sample the cerebral spinal fluid and send it to the laboratory. And when we analyze the cerebral spinal fluid, we can often get a lot of information about what's happening in the tissue of the brain and the spinal cord because it's a relatively leaky barrier. The second major function of ependymal cells is to participate in secretion of the cerebral spinal fluid. So secreting CSF, cerebral spinal fluid. Specialized ependymal cells and capillaries form little tufts in some of these spaces in the brain. And this is actually where the cerebral spinal fluid is secreted into these spaces, so that there will be capillaries very close to the ependymal cells. And in these little tufts, fluid will be secreted across the ependymal cells to create the cerebral spinal fluid.