the Skeletal System?
Your Skeletal system is all of the bones in the
body and the tissues such as tendons, ligaments and cartilage that
Your teeth are also considered part
of your skeletal system but they are not counted as bones. Your teeth
are made of enamel and dentin. Enamel is the strongest substance in
How does the Skeletal System help us?
The main job of the skeleton is
to provide support for our body. Without your skeleton your body would
collapse into a heap. Your skeleton is strong but light. Without bones
you'd be just a puddle of skin and guts on the floor.
Your skeleton also helps
protect your internal organs and fragile body tissues. The
brain, eyes, heart, lungs and spinal cord are all protected by
your skeleton. Your cranium (skull) protects
your brain and eyes, the ribs protect your heart and lungs and
your vertebrae (spine, backbones) protect your spinal
Bones provide the
structure for muscles to attach so that our bodies are able to
move. Tendons are tough
inelastic bands that hold attach muscle to bone.
Who has more bones a baby or an
Babies have more than adults! At birth, you have
about 300 bones. As you grow older, small bones join together to make
big ones. Adults end up with about 206 bones.
Are bones alive?
Absolutely. Old bones are dead, dry and brittle.
But in the body, bones are very much alive. They have their own nerves
and blood vessels, and they do various jobs, such as storing body
minerals like calcium. Bones are made of a mix of hard stuff that
gives them strength and tons of living cells which help them grow and
What is a bone made of?
A typical bone has an outer layer of hard or
compact bone, which is very strong, dense and tough. Inside this
is a layer of spongy bone, which is like honeycomb, lighter and slightly flexible. In the
middle of some bones is jelly-like bone marrow, where new
cells are constantly being produced for the blood. Calcium is an
important mineral that bone cells need to stay strong so keep
drinking that low-fat milk!
How do bones break and heal?
Bones are tough and usually don't break even when
we have some pretty bad falls. I'm sure you have broken a big stick at
one time. When you first try to break the stick it bends a bit but
with enough force the stick finally snaps. It is the same with your
bones. Bones will bend a little, but if you fall the wrong way from
some playground equipment or maybe your bike or skateboard you can
break a bone. Doctors call a broken bone a fracture. There are many
different types of fractures.
Luckily, bones are made of living cells. When a
bone is broken your bone will produce lots of new cells to rebuild the
bone. These cells cover both ends of the broken part of the bone and
close up the break.
How do I keep my bones healthy?
Bones need regular exercise to stay as strong as
possible. Walking, jogging, running and other physical activities are
important in keeping your bones strong and healthy. Riding your bike,
basketball, soccer, gymnastics, baseball, dancing, skateboarding and
other activities are all good for your bones. Make sure you wear or
use the proper equipment like a helmet, kneepads, shin guards, mats,
knee pads, etc... to keep those bones safe.
Strengthen your skeleton by drinking milk and
eating other dairy products (like low-fat cheese, frozen yogurt, and
ice cream). They all contain calcium, which helps bones harden and
What is an
An x-ray image is produced when a small amount of
radiation passes through the body and strikes a sheet of sensitive
film placed on the other side of the body. Bone, which contains
calcium, does not let much radiation through and results in white
images on the x-ray film. Radiologists are doctors who are specialists
in reading and making sense of X-rays, and they help other doctors
figure out what's going on inside you.
What's up with joints?
Your skeleton has over
200 joints. Joints are where bones come together. Ligaments are
strong inelastic bands of connective tissue that help hold bones
together at joints. Joints allow your body to move in many
different ways. Bending, twisting, stretching, running, jumping
and skipping are made possible by muscles and joints. In your
two wrists and two hands you have about eighty joints. Thanks to
these joints, you can tie your shoes, hold a fork, play
instruments, video games and many other things.
Where the bones come
together at joints there is a cushion of cartilage that helps
protect the bones. Cartilage helps to prevent
the bones from rubbing against each other and wearing down the
Between the joints in your spine the vertebrae are
protected by cushiony discs made of cartilage. Your nose and
ears also are made of cartilage. Try bending your ears and nose
but don't get carried away!