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Corpus Callosum

  1. Dec 9, 2012 #1
    I know the Corpus Callosum is in the Middle of the Brain and is about 4 inch long.

    It is a Band of Fibers that connect the Left and Right side of the Brain.

    And I know that the Fibers Brantch out is this why they say it is the Largest white matter in the Brain because it Brantches out?

    I ask because it is 4 inch Long and this is not that big so I thought it was because it Brantches out that makes it big.
  2. jcsd
  3. Dec 9, 2012 #2


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    Could you please provide a reference?

    It's the largest of the interhemispheric commisures.
  4. Dec 9, 2012 #3
    This is a link to a youtube video

    It says it is 4 inches long and is a Band of Fibers.
    Last edited by a moderator: Sep 25, 2014
  5. Dec 9, 2012 #4


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    I wasn't asking about the size. I was asking about the statement that it's the "largest". I know it's the largest of the interhemispheric commisures, but it's not immediately clear to me that the corona radiata isn't larger. Perhaps the corona radiata is considered to consist of several tracts, so the corpus callosum might be the largest white matter tract, but I'm not sure.
    Last edited by a moderator: Sep 25, 2014
  6. Dec 10, 2012 #5

    jim mcnamara

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    I think we look at largest in the sense of the "most stuff in it (volume)", rather than length of some dimension, when we refer to largest in this context. So, I agree with atyy.

    I can agree that 4 inches in length is large, but I don't know where that gets me.
    If you have a two foot long steel .5 inch diameter rod, and a steel ingot that is a 1 foot cube, which one is larger? The ingot.
  7. Dec 10, 2012 #6
    So the corpus callosum is a 4 inch Band of Fibers and this to me seems Short in length.

    But because it has Thousands of Tracks or Fibers this is why they say it is Larg right?
  8. Dec 10, 2012 #7


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    In signal conduction, there are two important dimensions: the cross-sectional area and the length.

    The resistance of a classical resistor goes up with length and down with cross-sectional area, so if you're talking about positive benefits, you usually talk about the cross-sectional area itself.

    In biological systems, length doesn't attenuate signal because of the nature of all-or-nothing firing (of course, it does attenuate passive currents). But it still takes more time to travel longer lengths, so lengths is still a "negative" as far as signal conduction is concerned.

    So yeah, I think "large" refers to the beneficial dimension, the cross-sectional area (which increases with the number of fibers.
  9. Dec 10, 2012 #8


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    In the OP you asked about "largest", which is at least comparative. But here you ask about "large". In science "large" or "small" are meaningless without further specification. You have to say large or small compared to what.
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