The Human Immune System

-Karthik Gurumurthy

The human body has many kinds of white blood cells to fight disease. They are  made inside your bones-in bone marrow-and travel in the blood. Each kind of white blood cell has a specific job in protecting your body from foreign substances. When you get sick, your bones produce extra white blood cells to increase its army of germ-fighting soldiers.

If a pathogen makes it past the first two defenses, it tries to get  inside your cells. But cell membranes recognize what is supposed to go inside the cells and do not easily let other things inside.

Sometimes, a pathogen can disguise themselves so they appear to be something that the cell membrance recognizes, and they are let inside where they can cause disease.

The third and toughest defenders in your immune system are the lymphocytes, white blood cells with memories. When lymphocytes find a pathogen, they create antibodies that attach to the pathogen. Once tagged with an antibody, a pathogen cannot infect a cell and other white blood cells know to destroy it.

Lymphocytes create several unique antibodies for each kind of pathogen they encounter. If the same pathogen invades the body again, the lympocytes remember it and create the antibodies for it before it can create problems.

Despite all of your defense systems, you can still become sick. Many people take medicine to fight disease. Some medicines are designed to kill pathogens. Others help the body function properly despite the disease. Vaccines are preventative medicines that teach your body to produce the antibodies ahead of time for certain pathogens. Above all, healthy eating is important to keep your immune system working properly.