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Featured New Organ (mesentery) found -- Congrats!

  1. Jan 3, 2017 #1
    We all got a new organ for Christmas, apparently.

    Article: http://www.sciencealert.com/it-s-official-a-brand-new-human-organ-has-been-classified
    Associated research article: http://www.thelancet.com/journals/langas/article/PIIS2468-1253(16)30026-7/abstract (login required, supposedly free)

    Is this news, or not news to anyone here? Biology is well out of my field.

    -Dave K
  2. jcsd
  3. Jan 3, 2017 #2


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    Oh, I thought you meant you got a new musical organ not a new organ organ, :-)
  4. Jan 3, 2017 #3

    jim mcnamara

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    Way back when, mesentery was considered disjunct pieces of connective tissue, analogous to coat hangers. Thanks for the link. We will see how well this concept fares in the literature.
  5. Jan 3, 2017 #4
    Alas, this one does not appear to have sonorous capabilities.
  6. Jan 3, 2017 #5


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  7. Jan 3, 2017 #6


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    It will be interesting to see what new functions, if any, get attributed to it.
    I find the structure unsurprising, but I have not had a medical education and I'm not too familiar with it (other than it gets in the way sometimes during dissections).

    The peritoneum is a continuous sheet of cells that lines everything in the abdominal cavity and is doubled over to make the mesentery. The mesentery links the lining of the intestines with the lining of inside of the body wall, so geometrically it makes sense to be continuous.
    The gastrointestinal (GI) tract is a tube going through the abdominal cavity (in a loopy way).

    In theory, such a lining could be a convoluted torus (GI tract all looped around in the inner part; this would leave no mesentery), or it could be a misshapen sphere with a fold in from one side to cover the tube down the middle (doubled over fold = mesentery).

    There could be a lot of things like blood vessels, nerves, and various cells in between the opposed folds. These may have some unknown (at least to me) functions (in addition to the mesentery cells themselves).
  8. Jan 5, 2017 #7
    I would rather have mesentery than dysentery.

  9. Jan 6, 2017 #8
    Being of a curious nature,o_O I looked into the mesentery on the online version of "The Lancet", I recommend reading the full text if your interested in learning more about this new organ.
    One of the earliest known depictions of it was done by Da Vinci, he drew it continuous and it appeared to converge centrally.
    For the following four hundred years it was depicted as it appeared in situ, suggesting contiguity. Since that time it's been depicted in various configurations, it's been known about for a long time but was very misunderstood.
    Here's a brief piece from the article, once again I recommend reading the full text, particularly the Physiology section.

    "Exciting opportunities for investigation are now emerging in relation to the role of the mesentery in health and disease. Mesenteric events are important in the pathobiology of diverse abdominal and non-abdominal disorders, including colorectal cancer, inflammatory bowel disease, diverticular disease, cardiovascular disease, diabetes, obesity, and metabolic syndrome. We therefore summarise the scientific findings of the mesentery's role in health and disease and explore the directions future investigations might take".


  10. Jan 6, 2017 #9
    RIGHT kind of silly questions but do our animal companians have this organ too? eg dolphins or dog
  11. Jan 6, 2017 #10
    Good question I think.
  12. Jan 6, 2017 #11
    Thanks for the news! We'll follow ...
  13. Jan 6, 2017 #12


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    It should be present in all vertebrates.
    I can't say for sure, but abdominal body cavity and organs are pretty well conserved.

    Its certainly in mice, cats, frogs, and fish, whose internals I have seen.
    Finding a vertebrate without a mesentery would be surprising.
    Vertebrates = mammals, birds (and dinosaurs), amphibians, reptiles, fish and shark-like animals.
    Hagfish and lampreys are closely related to, but not always classified as vertebrates. I would also expect them to have it.
  14. Jan 6, 2017 #13
    So I'm trying to understand... It has always been present, of course, but we didn't realize it was connected. Is that correct? What made it difficult to see this and what changed to make it easier to see later?
  15. Jan 6, 2017 #14
    Now that we have this organ (recognized) can we expect to see people being diagnosed with mesentary cancer, or some kind of mesentary disorder? When can I expect to see drug companies selling me prescriptions for real or imagined diseases like "[something] mesentary [something] syndrome"?

    Because, let's face it, we are great at messing up our organs!

    -Dave K
  16. Jan 6, 2017 #15
    Or perhaps for a change there will be an organ that never gets sick! ... That's what I would like to see!
  17. Jan 6, 2017 #16


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    The details of how abdominal organs of different vertebrate animals varies. Not all animals (some fish) for example have a big obvious stomach, some (birds) have a gizzard.

    The basic vertebrate body plan is often described as a tube within a tube. The interior tube goes from the mouth to the anus. The outer tube the ectoderm (skin basically). There is also a lot of mesoderm (middle layer) generally filling the space in between. The body cavities (such as the abdominal, thoracic, and heart cavities and spaces in the mesoderm in which other things reside. The GI tract runs through the abdominal cavity from where the esophagus comes down to the stomach, through the large and small intestines and out the bottom to the anus (see here for human version). These relationships are set-up during gastrulation in development, when the body plan and main body parts are established. Other groups of animals can have different body plans with different relationships among analogous parts.

    This can be due to enlargement of different parts like the stomach, small intestine, large intestine, the overall length of the different parts and the total, and various parts that branch off of the main tube (such as (in humans) the appendix, and various abdominal organs the develop from the surface of the tube (side facing the body cavity, not the lumen of the gut, where the food etc. is) and higher up in the thoracic cavity, the lungs) the overall tube shape can be obscured, unless you pull it all out.

    The different lifestyles of different species have selected for different structural and physiological features.
    Since material exchanges occur across surface areas, greater length, diameter, and internal folds have been selected for when more exchange is needed.
    Some animals have unusual (to us) out-pocketings of the basic tube, but regardless of all these variations, it is still topologically a tube going through a cavity. In humans, it is just twisted up, enlarged in places and looks like a mess (bunch of pictures here).

    The peritoneum lines the cavity and everything in it. It arises early in development when the tube structure is simpler and maintains it structural relationships as things develop and become more complicated.
    It has probably escaped notice by doctors because it has not been stylish to cut open human abdomens and pull everything out for a few hundred years.
    And those most likely to do it probably did not care a lot about anatomical details.

    Doctors are frequently not so aware of non-human biology. It would be interesting to see what the veterinarians think of this stuff.
  18. Jan 6, 2017 #17
    The full text is free, just create an account, Plenty of good info.

    "Improved understanding of the normal mesenteric shape enables identification of mesenteric abnormalities which in turn permits investigation of the relation between mesenteric abnormalities (position and nature) and disease. The multilevel contiguity between the mesentery and adjacent organs provides a structural platform to maintain homoeostasis, but also provides a means for disease spread. A mesenteric-based approach to disease classification therefore has broad applicability. We provide a brief description of its application to several common disorders, including primary and secondary mesenteric abnormalities (mesenteropathies)".
  19. Jan 6, 2017 #18


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    Seems they are already known:
    "Mesenteric tumors are uncommon lesions that are generally considered inclusive of similar lesions of the omentum. Primarily anecdotal references to this class of tumors have been made since the beginning of the 20th century. In 1936, Hart provided the earliest clear description of solid mesenteric tumors"
    from here.

    Its not that the things was not know. The article talks about how it being one piece was not appreciated.
  20. Jan 6, 2017 #19
    Is it related to Fascia? As I understand it there are some who say the Fascia have been overlooked historically in terms of importance and complexity of function because it was always in the way of dissection and so was not well analyzed as a continuous system.
    Last edited: Jan 6, 2017
  21. Jan 6, 2017 #20


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    Fascia is a different thing.
    Not in bodies cavities, but found in more " solid" areas of the body, like between and among the cells of muscles.
    Its a generalized connective tissue.
    Can be in sheets around muscles or between them and as a filmy diffuse network between things like skin and muscles.
    Its not often a sheet like structure histologically, like the peritoneum or mesentery are.
    I don't know much about what it does other than connecting things together with varying degrees of tightness.
  22. Jan 9, 2017 #21
    Where have you heard that? I have heard it from yogi/alt-medicine types. Let's not discuss them (it violates TOS) but if you have heard any claims from credible sources of this sort I'd be interested in knowing.

    -Dave K
  23. Jan 10, 2017 #22
    I'm on the same page.

    Full disclaimer - I do go to a chiro. He suggested Myer's book "Anatomy Trains" as one he says "gets it right". And I am a yoga fiend (based on advice from my real spine doctor). But I am skeptical. I would like to know why the practice of Yoga seems to provide benefits - but it's gotta be science. I can't stand the new age crap that goes with it. Breathing and meditation are as gooey as my belief system gets.

    That said I did find this article which gives a nice summary of the debate and has some references. I know this goes off topic but since you are the OP. I haven't looked at the references.

  24. Jan 10, 2017 #23
    Yeah, we could easily get out of scope for Physics Forums , but it looks like our thinking is more or less identical here. (I do yoga and mindfulness meditation and all that).

    -Dave K
  25. Apr 1, 2018 #24
  26. Apr 2, 2018 #25
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