From what happens when you get food poisoning, to the simple question of what happens to your body when you get sick with just a cold, the human body is capable of amazing things. Read on to learn more!
You might only get sick once or twice a year, but that's because your immune system is on constant alert. There are many defenses that germs have to penetrate in order to get inside where they can wreak the most damage.
Tears and mucus contain an enzyme that breaks down the cell wall of many bacteria. Saliva is also anti-bacterial. Since the nasal passage and lungs are coated in mucus, many germs not killed immediately are trapped in the mucus and soon swallowed. Mast cells also line the nasal passages, throat, lungs and skin. Your skin, in fact, does more than you realize to keep you safe. Think about it, why doesn't mold grow all over you every night when you sleep? Natural defensive patrols on your skin keep bacteria from growing where it does not on that pear you left on the counter last night.Any bacteria or virus that wants to gain entry to your body must first make it past these defenses.
You Meet the Invader
Hi, virus or bacteria. Why are you looking at me like that?
So, it happens. And it happens all the time, trust me. Sometimes invaders get past your outer defenses and -usually- embed in your throat. What happens next? If it's a known criminal that's been in you before, your body already has the cure. You won't even notice that you've been invaded because the invader will be put down so hard, it won't have time to call for its mommy. Our bodies store the keys to unlocking and destroying any virus it's ever previously met.But if it's new... or mutated enough that our security system doesn't quite recognize it? Well, then Virus particles or bacteria begin to wage war on the cell lining of your throat (if they entered through your mouth) and the mucus membranes often become inflamed and infected as those first casualties start to pile up. How does your body respond to this attack? It sends an increased flow of blood to these membranes. A higher volume of blood helps send forth a greater army of antibodies and white blood cells, which are the foot soldiers of your immune system.
Different Kinds of Invaders
There are two basic kinds of enemies your body is on the lookout for (there are others - like allergens and toxins, but these two are the ones that give you your standard cold and flu).
Bacteria are single-celled organisms that are much simpler than your own fancy cells in that they have no nucleus. Bateria are alive, and are completely independent organisms able to eat and reproduce - sort of like mini fish swimming in your body. Under the right conditions, one bacteria can divide into two separate bacteria perhaps once every 20 or 30 minutes. At that rate, one bacteria can become millions in just a few hours.
The kinds of wonderful things bacterial infection causes? Acne, food poisoning (E. coli, Salmonella, etc), Leprosy, Tonsillitis, eye styes, Pneumonia, Tuberculosis, Staph infections and Lyme disease. Bubonic Plague and Smallpox were both bacterial.
A virus is different. A virus is not really alive, it is nothing but a fragment of DNA in a protective coat. The virus comes in contact with a cell, attaches itself to the cell wall and injects its DNA into your cell. The DNA uses the machinery of your own cell to reproduce new virus particles - particles that are released to invade more cells. A virus turns your own cells into mini-copy machines to replicate itself into a vast army.Viral infections include: Rabies, Chickenpox, influenza, Herpes, HIV/AIDS, HPV, infectious mononucleosis, Mumps, Measles, Rubella, Shingles, gastroenteritis (stomach flu), Viral hepatitis, Viral meningitis, and Viral pneumonia.
As far as the virus is concerned - and think of it like a Terminator, since it's not really alive - the purpose of replication is simple. Just survival. No longer term goals. By makin' copies of its genome and packing those copies into viruses, it is able to continue infecting new hosts.
Now, bacteria is different. Bacteria is not only a living organism, it carries all the tools it needs for growth and multiplication and it can reproduce on its own, asexually. In case of sexual reproduction, certain plasmids' genetic material can be passed between bacteria. Most kinds of bacteria are harmless and some are even helpful... the bacteria in our intestines - for example - are very helpful in aiding digestion.An important thing to note about the difference between these invaders - antibiotics will only work on bacterial infections. Viral infections? Dump every antibiotic known to mankind down your face hole - it will do nothing. (Actually, don't do that - overuse of antibiotics is a real and growing problem).