The Immune System
Our body has defenses that help us to fight off invading viruses and bacteria. It is particularly useful when an illness is a cough, sneeze, handshake, or doorknob away. Our bodies maintain three lines of defense: the skin, secretions of mucus/tears/sweat/saliva, and white blood cells.We are born with some disease fighting capabilities, these are called innate immunities.
First Line of Defense This is a non specific defense. Meaning it does not target specific illnesses, but tries to stop all kinds, and is non responsive. this done with the integumentary system, the skin. The skin is a nonspecific defense because it wards off viruses and bacteria with out allowing them into our body. Now they can still find their way in through any of the openings on your face, or an open wound.Tears and saliva have a special enzyme that breaks down the cell wall of bacteria. the nose and throat have a mucus that helps catch pathogens(disease causing agents like bacteria or viruses). Sneezing and coughing help clear these unwanted pathogens from their respective airways. The bacteria either go out of the body or get swallowed into the acidic environment of the stomach. |
The Second Line of Defense
If a pathogen makes it past the first line, the second line of defense becomes active. It is also nonspecific despite that it is supported by white blood cells and inflammation. Inflammation is caused by white blood cells moving to the infected tissue and calling in for more white blood cells. Some white blood cells destroy pathogens by eating them, some release a histamine. Ahistamine is a chemical that helps destroy toxic agents released by the pathogen, and is the primary cause of the inflammation. White blood cells can also release a chemical that causes the hypothalmus to elevate the body temperature, trying to make the environment unsuitable for the pathogen. |
Vaccines and Antibiotics
- Vaccines are shots that help give you an immunity to a virus
- Antibiotics are usually pills that help you fight off bacterial infection