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Title: Sensory and motor neurons, glial cells Post by: ehd123 on Sep 26, 2014 It is known that glial cells outnumber by many folds and surround neurons.
There are 4 different types of glial cells: astrocytes, oligodendrocytes, ependymas and microglial cells. Oligodendrocytes' main function is to myleinate internodes of axons in the central nervous system. the equivalent to these oligodendrocytes in the peripheral nervous system are the Schwann cells. My question is, which cell myelinates the sensory and motor neurons? Title: Re: Sensory and motor neurons, glial cells Post by: ochorios on Sep 27, 2014 Allow me to explain ^-^
Myelin is used to speed up transmission over distance. especially in the long neurons, right? So, in the brain, there aren't long distances to traverse, so there's no point in the myelin it won't speed up the signal that much. Also, the brain is very compact, there's reallly not much empty space, there's simply not enough room for myelin. :nerd: Hope that helps, if not, please feel free to ask more. Title: Re: Sensory and motor neurons, glial cells Post by: ehd123 on Sep 27, 2014 Hello ochorios
Thank you for the help. :angel: However I would like to correct something here. The myelin is not just for speeding up the signal, it is also a protective covering for the axons providing them with a route. It i a necessity for all of our body's wirings because it possess a certain selectivity that helps pass on the signal from one neuron to another and what have you. Furthermore, there may not seem to be any spaces in the brain. But in fact, there are a lot of openings and ventricles that are being filled up by ependymal cells. These cells are similar to cuboidal epithelial cells and simply line these opening in our brain. They also possess microvilli-like structures that are called tanycytes which are responsible for making more surface area. But still, that doesn't answer the question, which cell myelinates our motor neurons :( |