Carcinogens and Cancer
[Figure 1] What’s the worst thing you can do to hurt your health? Besides pathogens, many other dangers in the environment may negatively affect human health. For example, air pollution can cause lung cancer. It can also make asthma and other diseases worse. Bioterrorism is another potential threat in the environment. It may poison large numbers of people or cause epidemics of deadly diseases. But the […]
HIV AIDS
[Figure 1] How long can a person live with HIV? Years ago, a diagnosis of an HIV infection was a death sentence. Not today. With the proper medical treatment, an individual can live well over 10 or 20 or more productive years with an AIDS diagnosis. One of the most famous individuals with HIV is Earvin “Magic” […]
Immunodeficiency
[Figure 1] Which is stronger? You or little tiny pathogens? Usually you are. Normally your body can put up a strong defense against enemy pathogens. But what if it can’t? What happens if your immune system is “sick”? Immunodeficiency Immunodeficiency occurs when the immune system is not working properly. As a result, it cannot fight off pathogens that a […]
Autoimmune Disease
[Figure 1] Joint pain. Not an uncommon problem as you grow older. Is it due to normal wear and tear on the joints? Possibly. But rheumatoid arthritis is an autoimmune disease, which means the body’s immune system mistakenly attacks healthy tissue. Autoimmune Diseases Autoimmune diseases occur when the immune system fails to recognize the body’s own molecules as “self,” or belonging to […]
Allergies
Have you ever started to sneeze and not known why? A beautiful sea of flowers. A nice sight, unless you have an allergic reaction. It is not uncommon to have reactions to pollen. Allergies Your immune system usually protects you from pathogens and keeps you well. However, like any other body system, the immune system itself can develop problems. Sometimes it responds […]
Immunity
Is giving shots to young children a good thing? Many, if not most, children hated going to the doctor, as it often meant getting a shot. Why? The shot actually contained a weakened or dead pathogen. And putting some of that dead pathogen into you was a good thing. Immunity Memory B and T cells help protect the […]
Cell-Mediated Response
[Figure 1] Do cells really attack other cells? They sure do. Depicted here is a group of T cells attacking a cancer cell. When they can, the T cells search out and destroy “bad” cells. Cell-Mediated Immune Response In addition to the humoral response, the other type of immune response is the cell-mediated immune response, which involves mainly T cells. It leads to the […]
Humoral Response
[Figure 1] What are those Y-shaped things floating around the cell? They are antibodies, which are large proteins. And they signal specific antigens for destruction. It does help that the antigens are usually attached to pathogens. Humoral Immune Response There are actually two types of immune responses: humoral and cell-mediated. The humoral immune response involves mainly B cells and takes place in blood and lymph. B Cell […]
Lymphatic System
[Figure 1] What happens when your tonsils cause more problems than they solve? Almost all of us have had a sore throat at some time. Maybe you had your tonsils out when you were younger? Why? Your tonsils are two lumps of tissue that work as germ fighters for your body. But sometimes germs like to hang […]
Inflammatory Response
[Figure 1] What happens when an enemy gets past the first line of defense? For this running back to make it past the first line of defense, there usually has to be a hole or break in the line. He then runs into the secondary, or the second line of defense. Whenever the skin is […]
