Flashcards in Chronic inflammation II Deck (17)
What are characteristics of granulomatous inflammation?
Aggregates of activated macrophages having a squamous cell-like (epithelioid) appearance
When is granulomatous inflammation most frequently seen?
In response to a cellular attempt to contain an offending agent that is difficult to eradicate, such as indigestible substances
What is a granuloma?
A focal area of granulomatous inflammation consisting of a microscopic aggregation of macrophages that are transformed into epithelioid cells, surrounded by a collar of mononuclear leukocytes (lymphocytes and plasma cells)
What is granulation tissue?
Histologically, a proliferation of fibroblasts and new, thin-walled delicate capillaries in a loose ECM
What is the physiological basis of fever?
Cytokines stimulate PG synthesis in hypothalamic thermoregulatory center to reset the body temperature set point
Acute phase response is activated in response to what chemicals?
Exogenous (LPS) and endogenous (IL-1, TNFa) pyrogens
What are the roles of IL-1 and TNFa in the acute phase response?
Increase COX to convert AA into PG
What are the important acute phase proteins?
CRP, fibrinogen, serum amyloid A
Which cytokines upregulate the acute phase proteins?
IL-1, IL-6, TNFa
What are the functions of acute phase proteins?
Bind to microbial wall, opsonize and fix complement to promote bacterial clearance
What is the WBC count for leukocytosis?
15k - 20k
What is the WBC count for leukemoid reaction?
40k - 100k
Increase in absolute number of neutrophils seen in most bacterial infections
Increase in absolute number of lymphocytes, seen mostly in viral infections such as mononucleosis, mumps, German measles
Increase in absolute number of eosinophils, seen in asthma, hay fever, parasitic infections
Decrease in absolute number of WBCs, seen in certain infections (viral, typhoid fever), also seen in debilitated hosts or overwhelming infection