How does the body protect itself from disease and infection?
The immune system and blood cells. If germs get through the skin or mucous membranes, the job of protecting the body shifts to your immune system. Your immune system is a complex network of cells, signals, and organs that work together to help kill germs that cause infections.
Skin, tears and mucus are part of the first line of defence in fighting infection. They help to protect us against invading pathogens. You have beneficial bacteria growing on your skin, in your bowel and other places in the body (such as the mouth and the gut) that stop other harmful bacteria from taking over.
- Your body uses white blood cells to fight off the bacteria and viruses that invade your body and make you sick. The white blood cell is attracted to the bacteria because proteins called antibodies have marked the bacteria for destruction. These antibodies are specific for disease-causing bacteria and viruses.
- The blood has several types of white blood cells including neutrophils, bands, eosinophils, basophils, monocytes and lymphocytes. Each fights infection in a different way. Neutrophils, for example, are one of the body's main defenses against bacteria. Neutrophils kill bacteria by ingesting them.
- So, without further ado, here are the five most common infectious diseases.
- Hepatitis-B. According to current statistics, hepatitis-B is the most common infectious disease in the world, affecting some 2 billion people -- that's more than one-quarter of the world's population.
Updated: 2nd October 2019