Unit 4 - internal defenses

what are neutrophils?

the most abundant immune cells, making up ~60-70% of all immune cells in the body

what do neutrophils do?

they detect and eat pathogens through phagocytosis

which immune cells are the first to respond to foreign pathogens?

neutrophils

what are 2 characteristics of neutrophils?

very short lived but extremely mobile (amoeboid)

what % of WBCs are eosinophils?

~1-3%

what do eosinophils help fight?

parasites and some bacteria

what % of WBCs are basophils?

~0.5-1%

what do basophils help fight?

parasitic infections

what substances do basophils contain and what do they help with?

heparin and histamine to help deal with allergic reactions

where do mast cells tend to reside?

in mucous membranes and connective tissue

what are the functions of mast cells?

wound healing and microbial defense

what do mast cells granules contain and what are they used for?

heparin and histamine, used for severe allergic reactions (anaphylaxis)

what role do monocytes play?

anti-inflammatory responses

what can monocytes differentiate into when they reach an infection?

Macrophages or dendritic cells

where are dendritic cells found?

in parts of the body that come into contact with the external environment

which areas are examples of barrier immunity involving dendritic cells?

skin, respiratory, digestive, and urogenital areas

what type of cell are dendritic cells?

antigen presenting cells (APCs)

what are macrophages?

large phagocytic cells

where do macrophages travel?

through all parts of the body

where can macrophages sometimes adhere to?

fibers in specific organs, such as liver

what other function do macrophages have besides phagocytosis?

antigen presenting cells (APCs)

what do natural killer cells destroy?

our own cells that are virally infected and cancer cells

what does a well cell have?

a self-antigen and MHCI (major histocompatibility)

what happens to cells that are not well?

programmed into apoptosis