The Immune System - Diseases


http://www.youtube.com/watch?v=HNP1EAYLhOs
Natural Killer Cells are the most aggressive white cells in the immune system. They make up about 5% to 15% of the total lymphocyte circulating population. They target tumor cell and protect against a wide variety of infectious microbes. Natural Killer Cells are a very important factor in the fight against cancer. Immune Stimulation is the key to keeping the white blood cell count high and giving the Natural Killer Cells a chance to fight cancer and other diseases


Immunity is the ability to “remember” foreign substance previously encountered and react again, promptly. There are two kinds of immunity: active immunity, when the body is stimulated to produce its own antibodies, and passive immunity, where the antibodies come from outside the person’s body. Active immunity is usually permanent, and can be induced due to actual illness or vaccination. Passive immunity is not permanent because the antibodies are introduced from outside the body, thus the B-cells never “learn” how to make them. Some examples of passive immunity include antibodies passed across the placenta and in milk from a mother to her baby, some travelers’ shots, and the Rhogam shots we we discussed earlier this quarter. Because antibodies are only protein, they don’t last very long and must be replaced if the immunity is to continue.


After reading this paragraph from: http://biology.clc.uc.edu/courses/bio105/immune.htm. I understand that being immune to something means being protected against a certain disease. You are protected by it because your body remembers the type of disease you had, and therefore you are immune to it. There are two type of immunity: Active and passive. I remember my teacher telling me that you can be passive immune to something by breast feeding. Thats why mothers usually prefer it then bottled milk. Also, he told us that active immunity is gained by getting a disease. Therefore, if you have chickenpox, for example, you never have it again... Because your immune to it.