Antigen * Any molecule that is foreign to a white blood cell.
All cells is surrounded by a cell membrane and so then antigen is on cell membranes
Self markers * White blood cells identify as belonging to you and not an invader. * every person has a different shape self marker * Identical twins both have same self maker. * This is how body determines what is foreign and what doesn’t belong * Suppose a person needs a kidney transplant, someone else donates a kidney, but the person is also giving a self maker being introduced to the other self maker so white blood cell determines it as an invader and attack. * Any difference in surface, white blood cells attack * Fungal chemical called cyclosporine which inhibits immune system so no destruction (prevents transplant rejection) * Anything entering body will not have the self maker but something different
Antibody
* “Y” shaped receptor molecule with a binding site for a particular antigen * bind to and inactivates foreign proteins * Proteins made of amino acids
* disulfide bridges hold antibody together so it doesn’t fall apart * most antibodies look the same * Variable distinguishes the antibody, shape of the tip makes the difference (curve) * Antigen binding site refers to the variable region * antibody attaches to antigen to help destroy it * always have a particular antibody which fits the antigen perfectly like puzzle pieces * Epitope is a portion of antigen that antibody (variable) attaches to, (antigen binding site) * Antibody holds onto antigen allowing white blood cells to grab it and destroy it
Immunity ( 2 types)
Active vs. Passive
* Active occurs when getting an infection or vaccination * you make antibody yourself * great advantage b.c. if you make it yourself, you will be immune to that pathogen for many years * Active immunity lasts a very long time
* Passive is not making antibody yourself * occurs before you’re born while you are a fetus * mother gives some of the antibodies , so when you’re born you are protected from diseases she encountered * passive is donated to you * Don’t last very long * one method through mother or by doctor who gives shot readymade with antibodies in it
1918, flu killed 20 million people over a span of 18 months
Lymphatic system is battlefield of where white blood cells fight pathogens
Autoimmune disorders * body can’t tell what’s self and what’s not self destroying self * Antibody attack body cells (rheumatoid arthritis, fever, diabetes)
Immune system – (innate and adaptive)
Innate
* That which you are born with * first line of defense Is skin which protects you from the environment * skin is has ph that microorganisms don’t like to grow on, acidic * Skin sheds all the time , upper most (epidermal) cells are dead constantly falling off * the average person in 1 hour shed 1.5 million epidermal cell so microbes fall off * when skin isn’t dry (sweat), body takes on another defense b.c microbes go to the wet spots and produces lysozymes * lysozyme is a digestive enzyme which destroys wall of bacterial cell giving off an odor called perspiration * wax in ear prevents microbes from going in
Natural killer cells * examine body cells and eradicate everything that doesn’t belong * looks for anything that doesn’t belong * if sure of it or not, it still destroys * doesn’t know antigen * if cell becomes cancerous, cell membrane starts to change , sometimes cells are more rounded * natural killer cells go over to cancerous cells and produces an enzyme preforin * Preforin punctures holes so cell is destroyed and won’t be able to divide * better you care for yourself, the more natural killer cells in
