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Health and medicine
Course: Health and medicine > Unit 8
Lesson 2: Neural cell typesOligodendrocytes
Oligodendrocytes are glia cells in the central nervous system that serve multiple functions. Most importantly, they create the myelin sheath around neuron axons, which allows for faster and more efficient communication between neurons. Oligodendrocytes also interact with other cells to exchange substances and may have additional, less-understood functions. Created by Matthew Barry Jensen.
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- Why would one neuron need to be insulated from another? You mentioned that the oligodendrocytes insulate the axons of the nerve cells(8 votes)
- Good question. The neurons are not insulated from one another, but rather the oligodendrocytes use a lipid based myelin sheath to insulate the CNS axons in order to increase the speed and efficiency of their action potential. The myelin sheath is wrapped around the axon and allows the action potential to "skip" over itself, thus the action potential needs only to depolarize the nodes or "spaces" between the myelin sheath. I hope this helped to answer your question.(22 votes)
- is it right that oligodendrocytes produces myeline sheath that surrounded axon in CNS and schwann cell produces myeline sheath in PNS ?(3 votes)
- Yes, the oligodendrocytes produce myelin sheaths in the CNS and Schwann cells produce myelin sheaths in the PNS. However, one other thing of note: a single oligodendrocyte can myelinate multiple neuronal axons, while a single Schwann cell can only myelinate a single nueron's axon.(5 votes)
- how much charge do neurons produce? is it possible to be electrocuted from inside the body if there wasnt insulation?(1 vote)
- They use in the order of magnitude of millivolts. If you think that the resting potential of a cell is approx. -70mV and when it depolarizes it might reach a peak of approx. +40mV, that's only a potential difference of around 110mV! Your neurons cannot light up a light bulb let alone give you an electric shock. But it's plenty for the nervous system to do its job.(1 vote)
- can an oligodendrocyte be connected to more than one myelin sheath on an axon?(2 votes)
- Yes, a single oligodendrocyte can myelinate multiple axons from different neurons.(1 vote)
- How long does it take to create the myelin sheath? Does it happen continuously in every part of the nervous system or does the growth occur in waves/stages and regionally?(1 vote)
- Are all axons in the CNS myelinated?(1 vote)
- No, some axons are unmyelinated and this may be for pathways involving pain perception etc.(1 vote)
- I am studying 2'3 cyclic nucleotide 3' phosphodiesterase ( cnp) is a oligodedrocyte, that means that it mylinates but how? Also how are oligodendrocytes and shwann cells connected?(1 vote)
- At, which specific substances exchanged influence the glial cells, neural, and oligodendrocytes? 2:46(1 vote)
- I am not sure that my question is related to this video.
My question is the thickness of the myelin sheath affects the speed of transmitting the signal through the neuron.
If it is too thick or thin, is there any problems on our body.(1 vote)- I do not know of an issue with the myelin being too thick. However, if the myelin sheath is damaged by toxins such as lead, or mercury, if there is a chronic lack of Vit B 12 and or if it is attacked by infection or by unknown causes such as Multiple Sclerosis, then the action potential can not travel correctly, and neurotransmitters are not released. Symptoms depend on the area of the injury but in general weakness, lack of connected thought etc. is likely. To read more, check out Wikipedia, an open encyclopedia that should be verified with other sources. https://en.wikipedia.org/wiki/Myelin#Demyelination(1 vote)
Video transcript
In this video, I want to
talk about oligodendrocytes. Oligodendrocytes are glia of
the central nervous system, derived from neural
stem cells and named from Greek words for
cells with a few branches. To show the structure
of oligodendrocytes, let me first draw a few neurons. I'll just draw their
somas and axons and I'll leave off
their dendrites. I'll draw the somas for a
couple of oligodendrocytes, one here and one here. And each oligodendrocyte
will extend a few processes, maybe up to
a few dozen processes each, towards the axons of neurons. And the structures at the end of
these oligodendrocyte processes will be the myelin
sheath for neurons that have a myelin
sheath on their axons. And you can see that each
oligodendrocyte can be creating segments of myelin sheath for
the axons of multiple neurons. And the different
segments of myelin sheath can be from different
oligodendrocytes on any particular neuron's axon. This material of
myelin is composed mostly of lipid, which is the
same kind of substance that makes up fat. So this is kind of a
fatty sheath around some of the axons of certain neurons. So let's take a little closer
look at this over here. And what we'll do
is we'll kind of cut through the
soma and the process in one of these segments
of myelin sheath, kind of like this. And then we're going
to look at it end-on, like we're looking down
from the end of the axon. So here, I'll draw the axon. And we've cut it. So we're looking at it end-on. So we're looking down
the tube of the axon. And the myelin sheath
is just the membrane at the end of the process of
the oligodendrocyte, that's wrapped very thinly
around the axon many, many, many times,
like a roll of tape. And I like to think of these
like the rubber coating on a wire, kind of
insulating the axon. And we'll get into
how information is transmitted along
axons in other videos. But basically, this
makes the transmission of information faster
and more efficient. And the myelin sheath is
still connected by the process to the soma of the
oligodendrocyte to maintain it. So each oligodendrocyte process
forms one segment of myelin on an axon. And each oligodendrocyte may
myelinate multiple axons. In addition to this function
of creating the myelin sheath, oligodendrocytes also
appear to influence neurons and other
glia, and vice versa, through exchange of a
variety of substances. There are also some
variably-shaped nonmyelinating oligodendrocytes in parts of
the central nervous system. But their function is
not yet entirely clear.