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.