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Is there a common name for protective layer of an organism?

  1. Oct 11, 2016 #1
    Hello, is there a common name/word/terminology for any protective layers on an organism, for example, skin on humans, bark on a tree, etc?
  2. jcsd
  3. Oct 11, 2016 #2

    jim mcnamara

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    Staff: Mentor

    Not really because of the multitude of higher plant and animal structures: ectoderm, dermis, epidermis, cuticle... and so on.
    For the best possible guess - I vote for epidermis. This is just a not very useful wild guess.

    PS: angiosperm bark is usually called phelloderm. Two names.

    The correct answer is: no. You can make a case for some of them being "most common" in certain contexts, maybe. But in the early days of Biology, researchers categorized everything often uniquely. Read: they went overboard naming things. If something has a name then you think you have a handle on it. When you may have no clue. Example: math graduate students will identify a type of problem and then not be able to solve it. Somehow naming something implies knowledge... not really but we often feel that way. It is called the cubbyhole effect. See, it is self-referential, and it has a name, too! It is a disease. :) .....aaahhhh! o0)

    So the outermost layer of plants can be phelloderm, spines, cuticle, trichomes (kind of hair), epidermis, glochids... ad nauseum. Same with animals - fur, spines, scales, exoskeleton.

    If you follow the development of tissues in the embryo of plants and animals you can see a common source, but in the full grown organism it is not always evident how a tissue is derived from other tissues.
    This requires a lot of painstaking work.

    Hair and fur are derived from follicles. Some invertebrates have an exoskeleton so the outer layer doubles as a skeletal structure - crabs, insects, bivalves are examples. Exoskeletons are quite varied.
    Last edited: Oct 11, 2016
  4. Oct 11, 2016 #3

    Fervent Freyja

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    Jim is correct with epidermis in humans. An organism can be considered a container within a container within a container, down to the subatomic level! There are many names for each level. There are waxes, bacteria, oils, etc. that also serve as protective barriers to the epidermis. Even water content in the surrounding atmosphere can be considered a protective 'layer' to the epidermis.
  5. Oct 12, 2016 #4
    Great! Thanks for all the responses. I was having a hard time finding the answer online... And It's so true, everything is wrapped into something else.

    I thought, perhaps there would be a word that would describe the main, "final", "solid" layer that outlines an organism. I would be satisfied with "outer layer". :)
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