What is Cancer?
Cancer is a word used to describe a group of diseases. Each one has its
own name. For example: skin cancer, lung cancer, and breast cancer.
Each has its own type of treatment and chance of being cured.
The organs and tissues of the body are made up of tiny building blocks called cells.
All cancers are a disease of the body's cells. In healthy
tissue these cells replace or repair themselves when they get worn
out or injured. Where there is cancer, the cells do not behave as
normal and keep on growing even when there is no need. These abnormal
cells can form a tumour.
Tumours can either be benign or malignant. Benign tumours do not spread to other
parts of the body, so are not called cancer. Malignant tumours are
made up of cancer cells that can spread from where they started
and can go on to damage other tissues and organs. This may happen
when a cell or group of cells breaks away and enters the bloodstream
or lymphatic system to form a new tumour somewhere else in the body.
This is called a metastasis or secondary tumour.
Lymphatic system
The lymphatic system defends the body against infection. It has
a network of tiny tubes like blood vessels that pass through most
of the tissues in the body. These vessels carry a clear watery fluid
called lymph.
There are hundreds of small bean-shaped glands called lymph nodes along this network.
Their job is to filter the lymph for foreign particles as it passes
through. They also allow blood cells called lymphocytes to protect
the body against infection.
Lymph nodes can be found in groups throughout the body such as in the neck,
armpits and groin. Sometimes you may become aware of these glands
if they become swollen or enlarged. More of these lymph nodes are
found grouped together in the chest and abdomen. Other parts of
the lymphatic system include the liver, spleen, thymus, tonsils
and bone marrow.
|
