7C Second Line of Defence Flashcards
Describe the second line of defence
- Non specific
- Rapid
- No immunological memory
What are the Antigen Presenting Cells?
- Macrophage
- Dendritic Cells
- Neutrophils
What do antigen presenting cells do?
- Performs phagocytosis
- Displays pathogen fragments on MHC II markers.
What do natural killer cells do
Destroys virally infected cells
What do Eosinophils do?
Target pathogens that are too big to be phagocytosed by degranulating on contact with pathogen, releasing chemicals
What do Mast Cells do?
Releases histamines that are responsible for inflammation
What are the non-cellular components
- Complement proteins
- Interferons
- Fever
What do complement proteins do?
Form pores in pathogen membrane which causes lysis(burst)
What do interferons do?
Interact with receptors on neighbouring cells which cause them to be less suscesptible to viral infection
What is the function of inflammation?
Increase the speed in which damaged cells are repaired/replaced
Steps of inflammation
- Damaged cells release cytokines
- Neutrophils arrive and release more cytokines to attract mast cells
- Mast cells release histamines causing vasodilation
- More white blood cells come
What is vasodilation and its purpose?
- Enlarging blood vessels (swelling and redness)
- Makes blood vessels for permeable to white blood cells
