We have mentioned that
bones are very rigid and
strong. They may, however, be
broken when they are exposed
to severe blows. What hap-
pens then? The bone repairs it-
self. Doctors set the broken
bone and make a plaster cast
so that the bone knits correctly.
There is nothing left for the
doctors to do because the bone
has its own repairing mecha-
nism. It is miraculous that a
broken bone heals itself and
becomes even stronger than
before. This miracle is worked
as follows:
The blood surrounding
the broken bone coagulates
and forms a "haematoma",
76
hematoma
new cartilage
tissue
new bone tissue
a large mass of
clotted blood sur-
rounds the broken
bone
the new bone tissue
is brought into shap
in a few months,
new bone tissue
forms.
a new cartilage tis-
sue appears on the
broken region
