immune response Flashcards
name4 types of pathogen and an example
protoctista - malaria caried by vector mosquito and potato blight carried by spores
bacteria - tuberculosis and ring rot in plants
virus - TMV, influenza and HIV
fungi - athletes foot and black sigatoka
how are diseases spread through proximity
in droplets coughed or sneezed out
list 5 factors that affect disease transmission
education on pathogen and how to prevent spreading
poorer areas
crowded areas
improper precautions
vaccination
hygiene
density of crops grown together
number of pathogens
areas with high number of vectors
list 5 plant passive physical defence against pathogens
bark made of dead cells which pathogens can not survive in
casparian strip
thick waxy cuticle
closed stomata
cellulose cell wall
list five plant passive chemical defences to pathogens
toxic compounds
lignin in xylem
sticky resin traps pathogens (jurassic park)
receptor molecules that trigger active defence
enzyme inhibitors
list 5 active defence plant mechanisms against pathogens
depositing callose in plasmodesmata and in sieve pores in phloem
killing of infected area
callose and lignin deposited between cell wall and membrane
humoral non specific immune response
skin has layer of dead cells
sebum produces on skin surface kills pathogens
mucus membranes
sneezing and coughing
lysosomes in tear ducts
describe the enzyme cascade for blood clotting once the skin (epithelial cells) has been cut
platelets come into contact with collagen
platelets form a barrier
platelets release clotting factors causing thromboplastin (with ca2+) to turn prothrombin into thrombin
thrombin turns fibrinogen into insoluble fibrin
fibrin creates a mesh that traps more RBCs and platelets forming a clot
describe and inflamed area
Pain
Redness
Immobility
Swelling
Heat
how does inflammation occur
mast cells detect pathogens and release histamines
histamines cause blood capillaries in area to vasodialate and makes the walls of the capillaries more permeable with small pores
neutrophils have loved nuclei so can fit through these pores and kill pathogens via phagocytosis
what’s a neutrophil
phagocytes which do phagocytosis
macrophages which do phagocytosis and present pathogen antigens on their cell surface
they are attracted to cytokines and chemicals released by pathogens
describe the process of phagocytosis
neutrophil engulfs pathogen sealing it in a vesicle called phagosome
phagosome fuses with lysosome forming phagolysosome
hydrolytic enzymes in lysosome digest pathogen
broken down pathogen parts diffuse into cytoplasm
where do T cells mature
thymus gland where they are given cell surface receptors specific to an antigen
describe T cells function once pathogen enters body
complementary t cell binds to antigen of pathogen presented by macrophage (takes a while that’s why you stay sick for a while) this is called clonal selection
clonal expansion occurs whereb the T cell undergoes mitosis and differentiates to form T helper cells, T killer cells, T regulatory cells and T memory cells
what do each of the 4 types of T cells do
T helper cell releases interleukins (a cytokine) which activate B cells and attract pathogens
T killer cells bind to pathogen antigens and release toxic chemicals through holes in pathogen cell membrane created by perforins
T regulatory cells kill T killer cells once pathogen is gone to prevent autoimmunity
T memory cells stay in the blood stream waiting for reinfection
