Immunity and Disease 2

Cytotoic T Helper T- (stimulate B cell action)

Active Immunity Occurs when B cells encounter antigens and produce antibodies. – When your own B cells make their own antibodies. Active immunity can be – Naturally acquired during bacterial and viral infections (You get sick and make antibodies). – Artificially acquired from vaccinations. Vaccinations: when an agent that resembles the disease causing pathogen is injected and causes an immune reaction in the individual. (You get a vaccine for the flu your body produces antibodies to that flu particle.)

Types of Vaccines Vaccines can be made in many different ways today, but with all its is very rare that a person will become sick from the vaccine given. Types: – From a dead form of the pathogen. – From a weakened form of the pathogen. – From a biological structure of the pathogen (like a toxin or protein the pathogen makes). – From specific antibodies that are against the pathogen.

Passive Immunity Occurs when antibodies are obtained from someone else. – Naturally from a mother to her baby during breast feeding (naturally acquired) – Artificially from immune serum (like a persons blood plasma from transfusions (artificially acquired) Immunological memory does not occur. Protection provided by “borrowed antibodies” This type of immunity doesn’t last long because you only have the immunity while the cells are alive, once they die you cannot make any more.

Types of Acquired Immunity

Antibiotics Antibiotics are drugs given to someone that has a bacterial infection. – Antibiotics do not work against viral infections. The issue that arises if antibiotics are not used properly, is that bacteria can become resistant to the antibiotics (the drug does not kill the bacteria any more). – This is being seen today because of the overuse of antibiotics and using antibiotics for viral infections.

Disorders Allergies: when the immune system overreacts to a un-harmful foreign pathogen. – Can be allergic to foods, medicines, out door pollen, pet dander, insects, soaps and dies…etc. – When a person has an allergic reaction their body cells secrete a chemical called histamine. – Histamine: causes the symptoms of allergies: runny nose, watery eyes, rash, swelling, can even cause anaphylaxis (severe overreaction that can cause constriction of airways).

Disorders Autoimmune Diseases: when your own body’s immune cells attack your own tissue, because they see the tissue as foreign. Many times the cause is unknown – Examples: rheumatoid arthritis (swelling of the joints because the body attacks the tissue in the joint), type I diabetes (pancreas can be attacked and not produce insulin), Lupus (body attacks joints, organs, skin, etc.).

Disorders HIV: Human Immunodeficiency Virus that attacks T cells (weakens the immune system). – Transmitted via blood and body fluids. Can develop into AIDS – AIDS: Acquired Immunodeficiency Syndrome, when your body loses its ability to properly attack foreign invaders. The virus has attacked the Helper T cells- immune response is weakened Most individuals with AIDS will die of diseases like pneumonia or the flu because their body cannot properly fight the infection.