Immune system Flashcards
Neutrophils
• Most common type of granulocyte
• Often the first responders to sites of inflammation
• Attracted to cytokines
o In turn, attract additional white blood cells once they arrive to the site of tissue damage
• Can help moderate various infections and environmental trauma
o But they are mostly suited for bacterial attacks
• Counts are often elevated during the acute stages of inflammation and are the main component of pus
Eosinophils
• Much less common type of granulocyte
• Responsible for immune responses
o Especially allergic and asthmatic reactions
• Elevated eosinophil counts on a complete blood count (CBC) often indicate allergic reactions or parasitic infections
o Including those parasites that infect the surface of the skin (fleas and ticks; ectoparasites) and those that infect the intracellular spaces (endoparasites) such sas parasitic worms (helminths)
Basophils
Granulocyte
• Along with related mast cells are also involved in allergic responses and parasite infections
o Often responsible for the release of histamine
♣ Stimulates blood vessel dilation
Macrophages
–Monocyte
•Main role is to phagocytize dead cells and pathogens
•If a pathogen is ingested by the macrophage, the antigens are presented on the surface of the macrophage to stimulate other immune cells to mount a specific response
Dendritic cells
–Monocyte
• Even more focused on processing antigens and presenting them to other immune cells
o Therefore serve as important links between the innate and adaptive immune systems
• Often found in areas of the body where contact with the external environment is more common
o E.g. skin, intestine, mucous membranes
How do innate and acquired immunity work together?
o Innate and acquired immunity work together to protect the host and defend against invasions
♣ Phagocytic cells can stimulate production of specific T lymphocytes to assist in pathogen killing and destruction
• T lymphocytes, in turn, release cytokines which increases the killing activities of phagocytes
