BACKGROUND:
The common name for the combination of all the bones
in the body is called the skeleton. The skeleton has several important
functions:
a) a framework that provides a shape for the body;
b) a solid
anchor for attachment of muscles;
c) production of blood; and
d) protection
of the brain, spinal cord and other vital organs.
Living bone tissue varies in hardness. The outside of most bones
are very hard. Minerals give bone tissue its hardness. Inside
the bones is a soft material called marrow, which is responsible for the
production of blood cells. Cartilage is generally
found at the ends of bones that move against one another. Cartilage
is a smooth, flexible material that is tissue. Ligaments are
tissues that may be found at the ends of bones if the bones are still held
together. There are 206 bones in an adult skeletal system.
A child's skeletal system has up to 275 bones. Some of the bones
will fuse together as the child grows.
Bones articulate at joints and are held together there and allowed
to move with the help of ligaments. Bones and muscles are attached
to each other by means of tendons. This combination of muscle and
bone provides an extraordinarily effective means of movement.
PROCEDURE:
- Give groups of students a skeleton. Ask
students to compare the skeletal model with their own body.
They can compare by counting the bones of each of the models and
see if they have the same number.
- Give students either the Human Body Placemat or the worksheet
of a skeleton, to count how many bones there really are. As they will find
out, most skeletal models are incorrect in one way or another. Note
that some books have varying numbers, because different numbers of bones
appear at different growth stages. Younger children have more bones
because some of them will fuse in later life.
- Use the Box of Bones puzzle to show students where
the major pieces go together. After you show them the electronic
version provide them with the real Box of Bones and challenge them to
put it together especially by looking at the other skeletons to help
them along.
