How do bones avoid veins?

Discussion in 'Biology & Genetics' started by Gawdzilla Sama, Oct 23, 2019.

  1. Gawdzilla Sama Valued Senior Member

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    Short version for subject line. Expanded it would be "I saw a triceratopsian shield* that had grooves in it for veins. I'm wondering how the bone shaped itself to provide that channel?"

    The groove would provide protection for the veins on three sides, and if deep enough the vein wouldn't protrude above the general level of the skin on the shield.

    *Rather like an elephant ear with a bone plate in it. Just wondering. I'm sure Jack Horner could explain it, but I don't like him much.
     
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  3. spidergoat Liddle' Dick Tater Valued Senior Member

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    Evolution.
     
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  5. DaveC426913 Valued Senior Member

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    You're thinking on too large a scale - as if the shield is a single large growth. Think in terms of cell growth.

    The artery came first (otherwise there would be no nutrients for the cartilage/bone to grow).
    Then cartilage forms in interstitial areas between arteries.
    Then cartilage calcifies into bone.

    Bones don't "grow" in the way trees grow out of the ground. They "fill" into defined areas. Those defined areas are bounded by and constrained by the structure and chemistry of adjacent organs.

    (They do get larger - in concert with other tissues, such as arteries.)



    But sure, as SG suggests, protruding arteries would surely be selected against, after a few generations of bleeding out every time they squoze through a dense forest.
     
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  7. Gawdzilla Sama Valued Senior Member

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    But the bone is smooth on either side of the vein. The bone doesn't grow "normally" under the vein. Just curious.
     
  8. DaveC426913 Valued Senior Member

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    You're thinking of the bone as one monolithic structure that's shaping itself at a macro scale.

    Think of it at the cellular level. No given cell knows what the other 99% of the "shield" structure is doing. All it knows is what it's neighbour cells are doing and the structures immediately around it. It grows according to what is immediately around it including other organs, such as arteries.

    And remember, this was established while still an embryo. The arteries developed in-place, and the "organ" that will develop into a cartilaginous mass, eventually to become bone, also developed in-place.

    How does a given cell "know" it is next to an artery so it does not split and grow more cells into that space? I think the answer is that the cells are constrained by the boundary of the "sac" that will harden into cartilage. Being soft tissue, that sac has an indent where the artery is.
     
    Last edited: Oct 23, 2019
  9. Gawdzilla Sama Valued Senior Member

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    Yeah, but the "knows" part escapes me.
     
  10. billvon Valued Senior Member

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    Chemical messages between the blood vessel and osteoblasts.

    Angiogenesis is one of the more important processes in higher animals, and we have had a _very_ long time to evolve ways to get blood cells into organs and other structures. (In fact, angiogenesis works so well that cancer stimulates blood vessel growth; in effect, the cancer mass "asks" for blood vessels and your body supplies them.)
     
  11. Gawdzilla Sama Valued Senior Member

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    Ah, that makes sense. Very intelligent design.
     
  12. globali Registered Senior Member

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    check out what happens when a baby is born with coarctation of the aorta.
    In brief, there is a narrowing in the passage of blood through the aorta, so in some cases blood supply to the lower body can be impaired. What can happen is the phenomenon of notching of the ribs,which means that new collateral vessels develop to supply the rib cage directly from the aorta and the ribs are notched as new vessels pass through them....
     
  13. Gawdzilla Sama Valued Senior Member

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    That's what happens. I'm exploring how it happens, if you get the distinction. Just curiosity based on viewing a college student working on a five-foot wide shield from a topsian.
     
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  14. DaveC426913 Valued Senior Member

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    Please Register or Log in to view the hidden image!

     
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  15. Write4U Valued Senior Member

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    https://ufluidix.com/circle/being-a...-organoids-from-stem-cells-is-a-game-changer/

    I'll be posting a quote and link to my thread;
    Is consciousness to be found in quantum processes in microtubules?
    in the "Alernative Theories" subforum.

    See you there.
     
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  16. Gawdzilla Sama Valued Senior Member

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  17. Write4U Valued Senior Member

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    If you actually seek an answer to your question , you'll find it there. I'm forbidden to post anything to do with microtubules in other forums other than in a dedicated thread.

    But that's is where you'll find your answer, I even addressed it to you.............

    Please Register or Log in to view the hidden image!

     
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