|I am doing the rubber bone experiment to take
minerals out of chicken bones. I am using
vinegar. I want to learn how my bones get the
calcium from the milk I drink. How does the milk
get from my stomach to my bones?
Glad you wrote to us with such an interesting
question. I usually study marine animals and
plants that make light (kinda like fireflies, if
you have seen them?) and glow in the dark! If you
would like to learn about these plants and animals
that bioluminescece (pronounced BI-O-LOOM-IN-ES),
go to this website
(http://lifesci.ucsb.edu/~biolum/). This is
another part of science that is really
To answer your question about
bones, I did some internet research, and came up
with the following reply. I found out from the
that after your stomach breaks down the food
you eat (let's say it is milk that you drank,
which has lots of calcium!) it goes to the next
organ, called the small intestine. The food can
then be taken into into your bloodstream there.
Calcium travels around in your blood as very small
particles and can be placed in different parts of
your body, where you need calcium.
know there are MANY uses for calcium in your body
besides forming your bones? (Although as you
learned from your rubber bone experiment, that is
very important for us to be able to stand and
walk!) Calcium is needed so that you can move your
muscles, and so that messages can be sent through
your nerves to different parts of your body and
brain? Adults have 2 pounds of calcium in their
Once calcium is in your
bloodstream, some of it is collected from the
blood by special cells called osteoblasts
(pronounced AHST-E-O-BLASTS) that create your
bone structure (calcium with phosphorus crystals
and collagen proteins, a very strong material).
There are also cells called osteoclasts
(pronounced AHST-E-O-CLASTS) that break down your
bones. This build up and breakdown of bones is
something that happens all the time in your body,
because your bones are living organs!
are many more bone-builders than bone break-down
cells when you are young, so you form good, strong
bones! When some people get older, they develop
weakened bones that are easier to break because
more bone break-down is happening than
bone-building! Scientists are trying very hard to
find medicines that will help these people's bones
not break so easily.
Here's a website that
your Mom can help you read about bones, and the
disease that makes older people's bones
Neat question!I hope your chicken bones come out
really rubbery. They're lots of fun that
Anyway, your bones are hard
because of the this stuff called calcium
carbonate. It's a big word, but all it means is
that two things, calcium and carbonate, "stick"
together to make your bones hard. Did you also
know that calcium carbonate is the same as chalk
your teacher uses to write on the chalkboard?
Pretty neat, eh!
Anyway, when you drink
milk, it goes to your stomach and stays there
until your body is done with it. When it is in
your stomach, all the goodies which are in the
milk, including calcium, are taken out of the milk
and absorbed by your stomach. How does that work?
Well, your stomach has special little things
stuck to its walls (called transporters) which
absorb the calcium and other goodies and sends
them to your blood. Pretty neat, right? Then
your blood carries that calcium to your bones,
where it dumps off the calcium for your body to
make more bone. That's basically how
Now here's another neat
trick. If you have a small piece of chalk, drop
it in the vinegar and watch what happens. Pretty
neat! Is there any chalk left after a while?
Probably not. Remember how I told you that chalk
and your bones are made of the same stuff (called
calcium carbonate)? Well, when you put a chicken
bone in vinegar, it dissolves away the calcium
carbonate, just like the chalk gets dissolved!
That's why the bone is all soft. Remember that
your bone is made of more things besides
calcium carbonate, that's why your bone
didn't completely disappear. But because the
calcium carbonate is gone, your bones are soft. I
hope your project goes well!
I'm writing from Wisconsin, the dairy state, so
I'll tell you about calcium. Our bodies use
calcium in a lot of ways. Calcium helps our heart
beat and helps our muscles move. It also makes up
part of our skeletons. As you say, you eat cheese
and drink milk. The calcium goes into your small
intestine (gut) along with the rest of your food.
Then it is absorbed into your blood right through
the walls of your gut. When that blood passes
through your bones, little bone-building cells
grab onto it and make bone out of it. Your body
is constantly breaking down your bones and
building them up again. The bones you use more
get stronger. Their shape even changes a
Heavy exercise can actually break
down your bones. There's a great article on
losing calcium through sweating
Thanks for asking,
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