White Bluffs spokesman. [volume] (White Bluffs, Wash.) 1907-1938, 1927-08-26
(f~ UT father, how does the
VIZ lymph get back?" EVERY
time you move a muscle or

/(~ UT father, how does the
VIZ lymph get back?' every
time you move muscle or
breathe, you squeeze it out
of the spaces which end in openings
into special little vessels. Valves keep
it from ever getting back. So on and
on 1t has to go into large pipe, which
empties at last into the blood through
big vein in the neck near the heart.
It Is pushed on also a little by the
heart, and sucked on by the current
in the vein. Moreover, 1t is helped
along by the fact that it is different
in composition from the other fluids,
and so passes out into any fluid next
to it. This process is called diffusion"
But, father, what makes the blood
go round to all the cells?"
II don't wonder you ask. That is a
real job, isn't. it? For, you see, the
cells cannot live as we can, on meals
three times day. They must get air
| and food brought to them day and
night and all the time. So long as they
get that, they do not care where they
are, and they will therefore grow out
side the body just as well as inside,
If you also keep them warm. Then
you must remember what an awful
lot Of pipes we must have to reach all
the cells, and what an awful heap of
pumping we shall have to make our
pump do. Moreover, ours are far the
most wonderful pipes In the world.
They grow bigger or smaller just as
they are told.
"There is trap in the pipe. What
makes the trap shut? Why: because 1t
is valve or trap which opens only
one way, and the rubber, springing up
again, sucks or pulls up the lid. and
when you squeeze down, the lid closes
again, kerplunk! 1t is exactly like the
trap-door Of our attic; and don't you
remember the one we made to pump
out our boat, with a wooden flap, a
leather hinge, and heavy coat Of lead
fixed on the trap-door to shut it down.
Doesn't that work well?"
/ "Splendidly."
"Well, the heart has invented far
better valves for. itself, and it has
built two bulbs to make It throw
stronger than 1t could with one, and to
give a more even flowing current not
one that Jerks.
"We'n take the best pump In the
world-a good heart. So we have two
two-cylinder engines. as you see in the
picture One set pumps the impure
blood into the lung, and the other
pumps the pure blood into the body.
This pure blood carries the food and
air. The pumps lie side by side and
are Joined together, making a shape
something like the ace Of hearts
They throw twenty tumblerfuls in q
minute. and all the blood in the body
In one and one-half minutes. But II
you run q race or climb high noun.
tain all the blood In your body may
pass through in one minute. The first
pipes are large and are called arteries
or air thoroughfares.' They get small.
er, and smaller and smaller, like Alice
In Wonderland, till they are mere hair
tubes or capillaries, and then these
Join together and get bigger and bigger
again, till they are pipes called veins
4 1.-THE arteries are strong and thick
and very elastic. Can you guess why?''
because the heart pumps hard right
into them?"
Eyes, that Is part of the reason. But
there Is another, and a very clever
reason. You know those squeaker toys
with elastic bags that you blow up
don't you7 What makes them go or
squeaking SO long?' Fl
! "oh, the elastic bag squeezes the
air out slowly through the pipe"
!. "Exactly so. That is why the ar
teries are so elastic; because in be
tween the strokes Of the pump, they
are squeezing out through the pipe.
the blood which was forced into them
The splendid result is that the stream