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Fluids in the Human Body

  1. Apr 16, 2013 #1
    I recently learned about the pressure of the atmosphere against the human body. It just so happens that this force is in equilibrium with the human body, so we do not feel any pressure. Although if we fly an airplane, we do.

    This got me to thinking, what of the blood in our veins? Does this not exert a force outward, which I can only assume is in equilibrium with a force acting against it. So now, I have the pressure of the atmosphere acting on me, as well as a pressure from my blood acting in another direction. Is this correct? Are there any other fluids in the human body (mucus?) that I am neglecting?
  2. jcsd
  3. Apr 16, 2013 #2

    Andy Resnick

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    It sounds like you are neglecting Newton's third law.

    There are lots of fluids within the human body besides blood, bile, and chyme. Too many to list.
  4. Apr 16, 2013 #3


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    And of course there is the most important fluid in the body: water.
  5. Apr 16, 2013 #4
    Don't leave me hanging!
  6. Apr 18, 2013 #5

    So if the atmosphere exerts a force on the human body, then an equal force will be exerted from the human body. Is this correct?

    If my thinking is correct, why do increased pressures cause us pain or make our ears pop? Does it hurt our bodies to exert a greater force then what we are used to? If we go really deep into the ocean, there must be a point where the pressure overwhelms our body, and we get crushed.
  7. Apr 19, 2013 #6
    I'd say everyone forgot to mention Lymph, which is a major toxin removal system. It is distinguished from the circulatory system by lack of a pump such as a heart.
  8. Apr 26, 2013 #7
    dont forget the gas pressure, thats way more than the pressure in your veins, which is pretty much nothing.
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