Science Zone Human Body 4 24 08 SZ Human Body 1 The Lungs 4 24 08 SZ Human Body 2 What do they do The lungs by howardtheduck


									          Science Zone
            Human Body

4/24/08      SZ / Human Body   1
          The Lungs

4/24/08     SZ / Human Body   2
                   What do they do?
The  lungs take air
 into the body.
   We will discuss

    how in just a little
The air enters through
 the mouth or nose.
Goes down the wind
 pipe and into the
 lungs themselves.
They go through
 tubes to structures
 called Alveoli.

   4/24/08                 SZ / Human Body   3
                  What happens next?
 When    the air is inside, the lungs
  absorb Oxygen into the blood.
    The blood also releases Carbon
      Dioxide into the lungs.
 When the blood is given the Oxygen
  it goes through vessels to the heart.
 The heart then pumps the blood to
  the rest of the body, delivering the
  needed Oxygen, and picking up the
  waste Carbon Dioxide.
 Finally the lungs push the Carbon
  Dioxide out of the body.
 Our cells need Oxygen to live and
  do what needs to be done.
    Also Carbon Dioxide can poison
      our cells and must be removed.
 Together the Lungs and Heart play
  an important role in our lives.
  4/24/08                     SZ / Human Body   4
 How the Lungs Work – The Diaphragm
 The lungs   rely on pressure to inhale
  (breathe in) and exhale (breathe
 The lungs use a muscle called the
    When it tightens, the space in

     the chest is bigger.
    When it relaxes, the space in the

     chest is smaller.
 By changing the size of the chest
  cavity, the Diaphragm can bring air
  in and push air out of the lungs.
    But why does changing the size

     do that?
    Changing the size in this case

     changes the Pressure.
   4/24/08                      SZ / Human Body   5
       How the Lungs Work – The Physics
 When    the space in the chest is
  bigger there is more room, but
  nothing filling it. This lets air
  push its way into the lungs.
    The bigger space has less

     Pressure than the outside
     air, so it can push in.
 When the space is smaller
  everything gets pushed
  together and pushes the air
  back out of the lungs.
    The smaller space has more

     Pressure than the outside
     air, because everything is
     scrunched together, so air is
     pushed out.

    4/24/08                      SZ / Human Body   6
          How Hard Does Air Really Push?
 Anyone     who has gone deep in pool knows
  that fluids (like water) can push on your
 Air is actually a fluid too, it also pushes on
  all sides of your body.
 How light is “light as air”?
    Right now the air in the atmosphere is

      pushing on you.
    In fact you have about 370 pounds on you

      head right now!
 The air in our atmosphere actually pushes
  pretty hard, but it pushes in all directions.
 It has always pushed this hard, so we don’t
  even notice it!
 It is this Pressure that lets air push so easily
  into and out of our lungs.
    4/24/08                      SZ / Human Body     7

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