chapter 6, phagocytosis

margination or pavementing

adherence of leukocytes to endothelial cells

selectins

adhesion molecules that bind carbohydrate ligands

phagosome

an intracellular phagocytic vacuole that has been engulfed by small pseudopods(endocytosis)

diapedesis

emigration of cells through the endothelial junctions that have retracted in response to the same mediators

macrophage activation

results in increased size, plasma membrane area, glucose metabolism, number of lysosomes, and secretory products

adhesion molecules

selctins and integrins, the first step of phagocytosis

phagocytosis

the process by which a cell ingests and disposes of damaged cells and foreign material

5 steps of phagocytosis

1. opsonization, recognition of the target and adherence of the phagocyte 2. engulfment or ingestion, and formation of phagosome 3. fusion lysosomal granules within the phagocyte 4. destruction of the target

neutrophils

-also called polymorphonuclear neutrophil(PMN) -ingest bacteria, dead cells, and cellular debris -first to respond -is short-lived and becomes a component of the purulent exudate or pus -the pus is removed from the body via the lymphatic system

macrophages

-arrive 3-7 days after -are slower than neutrophils because they are sluggish and the chemotactic factor that attacts them is released by neutrophils -does well in acidic environments

monocytes

-largest normal blood cells have a nucleus that is horse-shoe shaped -produced in the bone marrow, enter the circulation, and migrate to the inflammatory site, where they develop into macrophages