Immune response summarised Flashcards
an immune response involves events that
happen locally, at the site of infection, and also at more distant sites e.g. lymph nodes
how are most pathogens kept outside the body
via epitheilail barriers like the skin (epidermis/dermis)- only cross during injury
After injury pathogens pass the epidermis and
establish infection in the underlying tissue
which cells engulf pathogens
phagocytic cells such as macrophages and neutrophils and dendritic
dendritic cells are activated by
binding pathogens- then leave infected tissue and migrate to a nearby lymph node
where are dendritic cells collected
in a draining lymph node
Where are T cells activated
in draining lymph nodes when dendritic cells present antigens
activated t cells turn into
effector T cells and activate B cells to secrete antibodies
effector T cells and antibodies leave circulation
ENTERING THE BLOOD STREAM AND LEAVE AT THE SITE OF INFECTION
WHICH INFLAMMATORY MEDIATORS INDUCE CHANGES IN BLOOD VESSELS NEAR INFECTED SITE
TNF-a
CD4 T cells
activate macrophages to become more cytotoxic
antibodies recruit
complement to lyse bacteria directly and opsonise them enhancing their uptake by macrophages
in the case of viruses activated CD8 T cells
kill any infected cells