pentamer joined by J chain, remain in blood vessels, first produced short lived.
majority of serum anitbodies (80%), readily enter tissues, cross placenta, protect against circulating pathogens, neutralize toxins, enhance phagocytic cells and complement system
mucous membranes, saliva, tears, breast milk, dimer, prevent microbial attachment to mucosal surfaces (intestines and respiratory), short lived (short immunity against respiratory infections)
in this type of hypersensitivity...
it lasts <30 min. systemic (shock, breathing difficulties ) or localized (hay fever, asthma, hives), antigen causing IgE to be produced
it lasts 1+ day, T cells and macrophages must migrate, transplant rejection, poison ivy, TB (chronic dieases), sensitized, cytokines, inflammation