Top 5 Facts about the Immune System

It’s true: while you’re sitting around watching TV, trillions of foreign invaders are launching a full scale assault on the trillions of cells that constitute ‘you’.
Collectively known as pathogens, these attackers include bacteria, single- celled creatures that live to eat and reproduce; protists, larger single-cell organisms; viruses, packets of genetic information that take over host cells and replicate inside them; and fungi, a type of plant life.
Bacteria and viruses are by far the very worst offenders. Dangerous bacteria release toxins in the body that cause diseases such as E. coli, anthrax, and the black plague. The cell damage from viruses causes measles, the flu and the common cold, among numerous other diseases.
Just about everything in our environment is teeming with these microscopic intruders… including you. The bacteria in your stomach alone outnumber all the cells in your body, ten-to-one. Yet, your scrappy microscopic soldiers usually win the day against pathogens, through a combination of sturdy barriers, brute force, and superior battlefield intelligence, collectively dubbed the immune system.
Top 5 Facts:
1) The cure can sometimes hurt
Sneezing, coughing, a sore throat, and fever are all means of expelling pathogens, so as annoying as they are, each one is necessary.
2) Immunity soldiers are everywhere
A single drop of blood contains around 375,000 white blood cells, and blood constitutes for seven per cent of your total body weight.
3) You can ‘borrow’ immunity
Antibodies in breast milk give babies temporary immunity from diseases their mother is immune to, preventing infancy infection.
4) It deals with internal troubles, too
In addition to fighting pathogens, T-cells fight the body’s own cancerous cells and some cancer therapies boost the number of T-cells.
5) It has trouble with change
Unfortunately you cannot develop immunity to the flu and common cold because the viruses are always mutating.

The immune system in action! how white blood cells attack a parasitic worm

The human immune system is our protector — its job is to defend the body against diseases and other damaging foreign bodies.