Inflammation 5 Flashcards
Define inflammation
inflammation of prolonged duration in which active inflammation, tissue destruction, and attempts at repair occur simultaneously
Explain the relation between acute and chronic inflammation
chronic may follow acute or can skip it
What are a few causes of chronic inflammation?
persistent infection
prolonged exposure to toxic agents
foreign bodies
autoimmunity
What are the main morphologic features of chronic inflammation?
infiltration with mononuclear cells
tissue destruction
healing by connective replacement - fibrosis
Angiogenesis + immature fibrous tissue =
granulation tissue
Compare chronic to acute inflammation
in acute inflammation there is vascular changes, edema, neutrophils
in chronic inflammation there are macrophages, lymphocytes, plasma cells
tissue destruction
fibrosis
What is the dominant cell in chronic inflammation?
macrophages
Where do macrophages originate?
bone marrow stem cell –> blood monocyte –> tissue macrophage
How can macrophages be activated?
microbial products such as LPS
or cytokines such as IFN -y
What does activation of macrophages result in
an increase in
cell size
lysosomal enzymes
metabolism
ability to phagocytose and kill ingested microbes
Where do macrophages accumulate? What does this lead to?
accumulate at sites of chronic inflammation
continued recruitment of monocytes from circulation OR local proliferation of macrophages
What is the role of lymphocytes in chronic inflammation?
involved in antibody and cell-mediated immune reactions
What is the role of plasma cells in chronic inflammation?
develop from activated B cells and produce antibodies at the site of persistent antigens
What is the role of eosinophils in chronic inflammation?
response to parasitic infections or allergies
Why are neutrophils seen in chronic inflammation?
important component of foci - acute and chronic overlap
