Test 2 Immunology Innate defences o Skin mucous membranes Skin physical barrier trillions of bacteria protecting you Inhospitable envorionment Mucous membranes have antibacterial enzymes Cilia can move obstruction o Nonspecific internal defenses Stomach acids and enzymes will destroy them Can be upset and many microorganisms can make it through and upset the balance Phagocytic cells white blood cells in extracellular fluid amoeboid shape destroy microbes by phagocytosis They pick up cellular debris and kill bacteria Natural killer cells WBC that destroy body cells infected by viruses and cancerous cells by punching holes in them Inflammatory response caused by large scale microbial invasion through a wound Histamine released in response to damaged cells Histamine increases blood flow and washes out the wound leads to red swollen and warm to the touch Other chemicals releases attract phagocytes Blood clotting walls off wounded area pus is just WBC dying Fever response to microbes establish major infection Low grades 102F are beneficial Slows microbial reproduction Enhances immune response o Specific Immune responses Cell Mediated immunity o Tissue damages Chronology Mast cells release stored histamine that were alarmed by the dead cells releasing chemicals Histamine increases capillary blood flow and permeability Phagocytes leave cappilaries and ingest bacteria and dead cells o Third line of defense Lymphocytes Begin their lives in bone marrow 2 tyes One called B bone cells Other called T cells In thalamus gland Large part of the specific immune response o Cell mediated immune response T cells Infected cells actual human cells o Humoral Immune response B cells Used on free virus Bacteria fungi protists toxins Doesn t attack human cells o Immune system recognizes non human cells and attacks them o When the immune system recognizes you you suffer an autoimmune disease where the immune system accidentally recognizes good human cells How do B and T cells recognize the foreign cells o They have either B or T cell receptors that signal if something is wrong in the other cell and this creates a reaction where either B or T cells are released to destroy the problem Cell o Steps Recognize the invader B Cells Antibodies proteins produced by a host to bind to and inactivate foreign particles B cell receptors imbedded in the membrane of the B cell o Unique binding site so can only bind to one antigen something that leads to the production of antibodies o About a hundred million B cells one of 80 million B cells will recognize one specific thing o These antibodies have 2 separate subunits a heavy unit and a light unit o Genes for antibody parts recomine during development Result in a random assortment of antibodies Some will bind to body s own proteins Those cells that respond to the body s proteins will be destroyed before full development o T Cell and B Cell variable regions look different for binding to different points o B Cells divide after being activated into two cells then another two one of which is a plasma cell containing a loaded rough ER with ribosomes Plasma cells produce free antibodies not attached to the plasma membrane They are the bullets of the immune system o The antigen binding site is in 2 parts one is the heavy part one is the short part aka Long and light parts These parts are variable and respond to one antibody out of 80million o Epitopes Antigenic determination T Cell o 1 Recognize the invader o T cell receptors on the surface of T Cells NOT ANTIBODIES Made by T Cells The t Cell receptor is composed of an alpha chain and a beta chain composed of a constant region and the variable region aka the end piece They act like antibodies when antigen binds to T cell receptors the t cell responds o Launch the attack Humoral immunity Antigens in blood encounter B Cells each with specific surface antibody B cells with appropriate antibody bind to antigen B cells divides rapidly o plasma cells release large amounts of antibodies into blood stream to fight infection o Memory cells provide future immunity to the microbe but don t release antibodies o Antibodies can neutralize the free virus opsomization eaten by a macrophage and activation of compliment system and pore formation most complex formation and actively destroys the cell by punching holes in it o Helper T cells coordinate the attack and helps B Cell mediated immunity cells Killing the target cells directly T cells receptors bind to antigen T cells divide rapidly producing 2 types of cells o Effector cells 3 types attack cells Helper t cells stimulate cell division in killer t cells and B cells HIV disrupts this process by destroying helper t cells Releases a chemical called cytokine that promotes cytokinesis in those cells Killer cytotoxic T cells destroy cells in widespread infecion cancer Memory T cells provide future immunity to infection MHC proteins that grab bad proteins and put them on the outside of the cell to be picked up by T cell receptors for attack Plasma B cells are attackers of the humoral response Killer T cells are the attackers of the cell mediated response they are short lived as the plasma B cells are Memory B and T cells live for years o Future re infections Respond to antigen by rapidly multiplying into plasma B cells and Killer o o T cells to evoke 2nd immune response much faster o Very rapid response so usually no noticeable symptoms of reinfection Allergies a type of immune response Fungi Archaea Protists o 3 types of ploidity haploid diploid and some other thing o Reproduction Produces zygote like structures but there is no embryonic stage Many fungi can go through sexual reproduction or asexual Because it is advantageous genetic variation drives evolution Both sexual and asexual reproducing fungi produce spores Fungal phylogeny o 5 divisions Chytridiomycota Zygomycota Glomeromycota Basitionmycota Ascomycota o Over 100 000 fungal species and more are added each year o Five divisions of the kingdom fungi o These divisions are based on dna sequence data on the presence of septa in the fungi and on the sexual life cycle
View Full Document
Unlocking...