The Immune System
What goes on inside our bodies?
When you get sick many things happen inside you.
When you get sick it means that a pathogen has entered your body. A pathogen is an organism that causes disease. For example when you get the flu a pathogen known as a virus enters your body. Because viruses are not alive you can't simply take antibiotics, your body has to do all the work. But, before you even get sick you body has 2 lines of defense to keep out pathogens. The 1st line of defense consists of a barrier of dead skin or your outer most layer of skin, muscus, saliva, tears , that contain lysozyme enzyme that break down bacterial walls and, acidic oil and sweat that kill bacteria. The 2nd line of defense is made up of the inflammatory response which increases white blood cell production and expansion of blood vessels which increases body temperature(fever). The infected tissue then becomes swollen and painful. If the pathogen makes it past all this the body then recognizes its there. The body recognizes pathogens by using lymphocytes and antibodies. Lymphocytes identify antigens(protein markers) on the pathogen and then bind to the pathogen in the process the pathogen is destroyed. The job of antibodies is to bind to antigens and basically mark them to be destroyed. Each pathogen has a specific receptor and antibodies are made to fit each one perfectly. This ties into the immune response which mean that since your body has already produced antibodies for the specific pathogen next time it tries to attack you your body will be ready to fight it.