All journeys must have a some start,
today it's blood entering your heart:
      Two pipes join at the top
      of your blood's first pit-stop;
your atrium is where it'll fast dart.

So through the tricuspid valve blood seeps,
and then to a ventricle it ekes.
      That cavity then squeezes,
      with the force of ten sneezes
like a wound balista releases!

Past the big pulmonic valve blood’s bumped,
and into another tube it’s dumped.
      The blood goes in a lung,
      and with air it is wrung,
and back to the heart it is pumped.

Thus, into the atrium blood flows;
But alas, the cavum shall then close
      and the blood can't quite fit.
      It's let out through a slit--
pushed through the mitral valve blood goes!

Then into a ventricle goes the stuff,
but out again it is in a huff!
      Sans reason and order
      it goes to the aorta
which makes sure your organs get enough!