Defence mechanism Flashcards
What is immunity
What is a antigen
Immunity-body protect from pathogens. Antigen - protein triggers immune system found on surface of cell
Example of immediate defence
Example of slow defence
physical barrier/phagocytosis.
Lymphocytes T mediated/B humoral. Lymphocytes distinguish own and foreign cell, as each cell has molecule on surface specific due to tertiary structure. 10 millions of them one have complimentary protein on surface to pathogen cause lymphocytes divide build number - clonal selection.
Process of Phagocytosis
Phagocyte identify foreign antigen on pathogen so moves closer along gradient attaches to pathogen chemical. Phagocyte engulf it forming phagosome. lysosome fuse with vacuole enzyme lysozymes hydrolyses bacteria
Lymphocytes are -
B -
T-
Slower but long term immunity. B- bone marrow , humoral with antibodies. T- thymus gland , cell mediated response.