Skip to 0 minutes and 6 seconds So if you look at a textbook or if you do a search on the web to look for an image of a neurone, what you’ll find is that you by and large see the same kind of picture. And that picture shows neurones having some consistent structures that you will see across all types of neurones. And some of those structures, in fact, you will see across all types of cells, so skin cells, liver cells, any other type of cell in the body. But some of the structures appear to be unique to the neurone.
Skip to 0 minutes and 36 seconds So if we start by drawing what we might think of as the cell consistent structures, we’ll see that we have a sort of mass of cell containing in the middle a nucleus. So every cell in your body has to have a nucleus containing the DNA, and this also contains other structures which acts as power houses of the cell. But as I said before, the liver cell, the kidney cell, any other cell would also have this kind of structure in it. But if we’re thinking about neurones, what are the particular and unique features that we might see? Well, emanating from the cell body, we will see long, thin, branched processes.
Skip to 1 minute and 28 seconds And these processes are known as dendrites or dendrons, and this word comes from classical language and the refers to the fact that these structures look a bit like the branches of the tree. Now, usually what we will also see is a long sometimes slightly thicker process, which goes a very long distance. And because this goes a long distance, I’m going to draw it having brakes in it. Now, this structure is known as the axon. And if we follow the axon all the way to its terminus, we see that again it will branch, and when it does so, it terminates in structures known as terminals or synaptic knobs.
Skip to 2 minutes and 21 seconds Now, sometimes you will also see the axon with other structures surrounding it, sort of sausage-shaped structures.
Skip to 2 minutes and 30 seconds And these structures are made of myelin, and myelin is a substance made by a type of glial cell. We’ve met glial cells already. And that aids the process going on in the axon, which we are going to talk about next week. So what it means that these cells, these neurones, have such specific structure? Well, it tells us that if they’ve evolved to have that, these structures must be important for function and therefore, at some point, we need to understand what processes are happening here, what processes are happening here, and what processes are happening here. And this is largely subject for next week.
The classical neurone
An introduction to the basic characteristics of an average neurone that we might find in the peripheral nervous system. We will cover their differences from and similarities to other cell types. Some of the potential implications of these basic structural characteristics for function of human neurones, including those in the brain can then be seen.
Image 1 - ‘Anatomy and physiology of animals motor neuron’ by Sunshineconnelly at en.wikibooks. Later version(s) were uploaded by Rlawson at en.wikibooks. CC-BY-3.0, from Wikimedia Commons
Image 2 - ‘Neuron’ from “Anatomy and Physiology” by the US National Cancer Institute’s Surveillance, Epidemiology and End Results (SEER) Program.
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