chapter 7 Flashcards
what are antigens?
any molecule that triggers and immune response
what are MHC 1 and MHC 2 proteins?
Both are self-antigens that mark as self so immune doesnt attack, MHC 1 expressed on all cells with nucleus. MHC 2 found on specialised cells of immune system
what are allergens?
substances that I.S recognises as non self and initiates immune response. EG : peanuts, dust, pollen
what are pathogens?
disease-causing agents, some have cellular structure. EG : parasite, fungi, virus, bacteria, prions
what are physical barriers of animals in 1st line of defence?
intact skin, hair (nose/eyes), mucus, cilia
what are chemical barriers of animals in 1st line of defence?
stomach acid, lysozymes in tears and saliva, sweat
what are microbiological barriers of animals in 1st line of defence?
bacteria on skin, flora on skin and gut
what are physical barriers of plants in 1st line of defence?
thorns, thick waxy cuticle, closing of stomata
what are chemical barriers of animals in 1st line of defence?
chitinase, phenols, oxalic acid (toxic to digest)
what do natural killer cells do ?
degranulate, force cells to undergo apoptosis, pucture and release cytotoxic chemicals, targets viral cells and cancer cells
what do mast cells do ?
degranulate, release histamines, important in inflammatory response
what do neutrophils do?
engulf pathogens, dies after activation
what do eosinphils do?
degranulate cells, release toxins
what are intereferons?
interferons signal to neighbouring cells to prepare for infection. they prevent viral spread and DNA replication
what happens during opsonisation?
complement proteins stick to outside of pathogen, makinig it easier for I.S cells to recognise.
what happens during chemotaxis?
complement proteins attract phagocytes to pathogen
what happens during cytolysis?
complement protein initiate MAC (membrane attack complex) where it puntures holes in pathogen, destroying pathogen
what are the steps of the inflammatory repsonse?
1) initiation : injured cells release cytokines to attract neutrophils, mast cells degranulate and release histamines
2) vasodilation : blood vessels dilate and become leaky, increased blood flow (redness swelling)
3) migration : phagogytes guided by cytokines to area, complemet proteins come
what are macrophages?
engulfs, antigen presenting cell, MHC 2
what is clonal selection?
when the B or T cell binds with the pathogen OR MHC 2 marker
what is clonal expansion?
rapid mitosis, dividied into many of the cell that has been matched
what is clonal differentiation?
B and T cells begin to specialise
what are antibodies?
proteins produced by plasma cells during adapive immune response that is specific to an antigen
what are the function of antibodies?
agglutination, opsonisation, neutralisation, immobilisation, activate complement proteins
what is the process of the humoral. immunity activation?
1) B cells match w/ pathogen or MHC 2
2) B cell confirms w/ T helper cell
3) clonal expansion
4) clonal differentiation (plasma or memory)
5) plasma cells release antibodies, mem cells remain
what is the process of the cell mediated immunity?
1) T cell match w/ pathogen or MHC 2
2) T cell confirms w/ T helper
3) clonal expansion
4) clonal dfferentiation (T memory, plasma, cytotoxic)
5) Cyto T leave nymph nodes to site of infrction, and induces apoptosis
what is maturation?
learning difference between self and non self cells
what is immunological memory?
T and b memory cells allow body to respond to previously encoutered pathogens more quickly and effectively
explain the relationship between an allergen, mast cells and histamines
Allergens react with specific antibodies which are attached to mast cells, thereby causing the release of histamines from the mast cells
