Immune+System

= = = __IMMUNE SYSTEM__ =

(Annie)

What is Immune System?

 * A body system that could fight back the infection and pathogens. (Nowicki, pg.945)

What is Pathogens?

 * Specific microorganism/germ that caused disease. (Nowicki, pg.941)
 * Can infect unicellular organisms from all of the biological kingdom ("Pathogen")

White blood cell and Proteins are weapons to fight pathogen in Immune System

 * White blood cell:
 * find and kill pathogens that past the external barriers (Nowicki, pg.946)
 * Physical barriers:
 * Skin-first line of defense to keep the pathogen away from the body because it surrounds to protect insides of the body (Nowicki, pg.945)
 * Physically block the invading pathogens (Nowicki, pg.945)
 * Produce sweat & oil to create a hypertonic & acidic environment so the pathogen can’t survive (Nowicki,pg.945)[[image:Picture.jpg caption="Biology, pg 945"]]
 * needs extra protection (Nowicki, pg.945)
 * Mucous membranes in these organs use cilia cover with sticky liquid to trap pathogens before they invade the body. (Nowicki, 945)
 * When pathogens pass physical barriers:
 * Circulatory system send signals of the exact place that get infected and transport specialized cells to the infection called Phagocyte cells (Nowicki, pg.946)
 * Phagocyte – a group of immune cells specialized in find and engulf (“eating”) pathogens (Nowicki, pg.946)
 * It also find and engulf with bacteria, viruses, and dead or injured body cell ("Pathogen")
 * After phagocyte, lymphocytes reach the infection (Nowicki, pg. 946)[[image:15-11_Phagocyte_1.jpg caption="http://www2.bakersfieldcollege.edu/bio16/images/15-11_Phagocyte_1.jpg"]]
 * T-lymphocytes / T cells to destroy body cells that are infected with pathogens. (Nowicki, pg. 946)
 * B-lymphocytes/B cells to produce proteins that inactivate pathogens that have not yet infected the body cell. (Nowicki, pg. 946)

__Extra Vocabulary__:
 * Antigens – protein stays on the surface of cells and viruses that helps the immune system identify unknown cell or virus. (Nowicki, pg.951)
 * Memory cell – specialized T and B cells to provide acquired immunity that “remember” previous invaded antigens.(Nowicki, pg.951)

**How body Response/destroys pathogens**
 * [|Antibodies (click here)]-proteins made by B cell, destroy pathogens in one of three ways (Nowicki, pg.947)
 * Make pathogen ineffective by binding to the pathogen’s membrane cause it to cluster so the phagocytes would engulf and destroy them easier. (Nowicki, pg.947)
 * It also activates a complement of protein that weakens the pathogen’s cell membrane.( Nowicki, pg.947)


 * [|Interferon (click here)] – proteins produces by body cell, already got infected by virus.(Nowicki, pg.947)
 * Cell release interferon (Nowicki, pg.947)
 * Cause body cells produce enzymes prevent viruses enter and infect the body (Nowicki, pg.947)
 * If virus can’t enter healthy cell there is no reproduce (Nowicki, pg.947)
 * Others cause an inflammation response. (Nowicki, pg.947)
 * [|Inflammation] - nonspecific response by swelling, redness, pain, itching, and increase temperature in your body (Nowicki, pg.950)
 * Mast cell release chemical (histamines) to response the pathogen attack. (Nowicki, pg.950)
 * Histamines cause cells in blood vessel' walls to spread out. (Nowicki, pg.950)
 * Fluid move out of blood vessel into the surrounding tissues. (Nowicki, pg.950)
 * White blood cell squeeze out of the capillary and move toward to the site of infection.(Nowicki, pg.950)
 * Outside circulatory system, white blood cell could fight the infection. (Nowicki, pg.950)
 * Pathogen defeated, inflammation stop, tissue repair. (Nowicki, pg.950)
 * Low fever-good (Nowicki, pg.951)
 * Produce interferon - stop virus from reproduce.(Nowicki, pg.951)
 * Speed up the process of white blood cell to mature to destroy pathogens.(Nowicki, pg.951)
 * More mature white blood cell, more quickly body fight off infection.(Nowicki, pg.951)
 * Hypothalamus (Part of brain that control eating, temperature) can’t no more control body temperature. (Nowicki, pg.951)
 * Enzyme control chemical reaction stop functioning. (Nowicki, pg.951)
 * Cause seizure, brain damage, even death. (Nowicki, pg.951)

**Immune Response:** >>
 * Cellular immunity - immune response that depends on T cell. (Nowicki, pg.952)
 * Phagocyte recognizes therefore its engulf pathogens and display the pathogens’ antigens on their membrane surface. (Nowicki, pg.952)
 * T cell bind to antigen-presenting cell and activate T cell. （Nowicki, pg.952)
 * T cell divides & separate into memory T cell and activated T cell. (Nowicki, pg.952)
 * Activated T cell bind to infected body cell and cause them to burst.(Nowicki, pg.952)
 * Humoral immunity - immune response that depends on antibodies. (Nowicki, pg.953)
 * A pathogen bind to a B cell then B cell engulfs pathogens and keep part of its antigen on its surface. (Nowicki, pg.953)
 * T cell binds to trapped antigen fragment and stimulates the B cell. (Nowicki, pg.953)
 * B cell divides, separated into memory B cells and activate B cell. (Nowicki, pg.953)
 * Activated B cells produce antibodies, cause pathogens to clump. (Nowicki, pg.953)
 * Phagocytes eat the pathogen clumps. (Nowicki, pg.953)

White blood cells sometimes cause tissue rejection after an organ or tissue transplant since:

 * Sometimes foreign tissues protein markers different from the body cell’ proteins and immune response can happen to attacked and rejected the transplanted tissue. (Nowicki, pg.954)
 * Cells with protein markers that fit white blood cells’ receptor molecule è foreign. (Nowicki, pg.954)
 * Cells with protein markers that not fit/interact with white blood cells receptor molecule è not detected by immune system. (Nowickipg.954)
 * Sometimes immune system loses sense of recognizing body healthy cell è attack healthy body cells (autoimmune diseases). (Nowicki, pg.954)

Similarities and difference between bacteria and viruses:

 * Similarities:Bacteria and viruses are 2 micro-organisms.
 * Different: bacteria is alive while virus aren't (it stays alive when it goes into T cell, cause T cell to stop function then stay alive as a host to reproduce).

**Vaccine:**
 * How vaccines work ?
 * Stimulating an immune response so sickness would not cause if the real pathogen infects the body. (Nowicki, pg.956)
 * Antigens in vaccine cause immune response, memory B cells are made (Nowicki, pg.956)
 * Memory B cell is stimulated when read pathogen binds to it (Nowicki, pg.956)
 * B cell quickly activates, make antibodies fight pathogen before sickness.(Nowicki, pg.956)

**[|HIV - human immunodeficiency virus](** Nowicki, pg.961 **)**

>>
 * Attack and weaken the immune system (Nowicki, pg.961)
 * Very dangerous pathogen, only live in human blood cells so they can’t survive outside for long. (Nowicki, pg.961)
 * Ways HIV transmitted:
 * Enter a person’s bloodstream. (Nowicki, pg.961)
 * Passing from person to person through sexual intercourse and could pass on to baby. (Nowicki, pg.961)
 * Use needle that the HIV person recently used (hypodermic-inject illegal drug; needle for tattoo-ing) (Nowicki, pg.961)
 * RNA that has 9 genes.
 * Reproduce in T cell:
 * HIV enter T cell causes T cell ineffective (Nowicki, pg.961)
 * T cell can't function in immune system (Nowicki, pg.961)
 * HIV alive as a host and reproduce (Nowicki, pg.961)
 * Higher risk of getting infection because once it reproduces in single T cell, there are thousands of new HIV before T cell eventually dies. (Nowicki, pg.961)
 * No symptoms occurs for a person with HIV, T cells becomes infected, can’t replace T cell fast enough, therefore immune system weaken, infection takes over, later causes AID (Nowicki, pg.963)

AID - acquired immune deficiency syndrome ( Nowicki, pg.963 )

 * Final stage of HIV-bring immune system to decline. (Nowicki, pg.963)
 * Fungal infections, tuberculosis, pneumonia, viral infections, and cancers (very few T-cell) (Nowicki,pg.963)
 * People’s body can’t fight AID so always result dead. (Nowicki, pg.963)
 * Very expensive treatment, only slows the disease, not cure (Nowicki, pg.963)
 * Combination of three to four antiviral drugs, five times /day, also very expensive drugs (Nowicki, pg.963)

CITATION:
"Pathogen." //Science Daily: News & Articles in Science, Health, Environment & Technology//. Science's Daily, 15 May 2011. Web. 15 May 2011. . Nowicki, Stephen. "Immune System and Desease" //McDougal Littell Biology//. Evanston, IL: McDougal Littell, 2008. 379-83. Print.