Path I Flashcards
Inflammation
a complex cytologic and histologic process involving blood vessels and tissues near a site of injury that is intended to destroy invaders and/or remove damaged tissue and initiate the repair process
acute inflammation: what kind of a process? What kind of cells? Timing?
exudative process (exudative: oozing of fluid or other materials from cells/tissues)
fluid and leukocytes, esp. neutrophils, leave circ and go to site of tissue damage
rapid onset
short duration (<48 hrs)
chronic inflammation: what kind of process? what kind of cells? timing?
proliferative process
inflammatory cells coexist (macrophages and leukocytes) coexist with repair processes (fibroblast prolif. and angiogenesis).
may follow unresolved acute inflammation or arise as the primary inflammatory response
slow onset and prolonged duration
abscess
pus- accumulation of dead tissue cells, inflammatory cells, and pathogen within a cavity formed by the disintegration of the tissue. surrounded by fibroblast prolif. and collagen
coagulative necrosis
cell death with denaturation and coagulation of cell proteins leading to preservation of cellular architecture with increased eosinophilic staining of the cytoplasm and loss of nuclear staining. (pink fuzzy stuff)
caseous necrosis
cell death with loss of cell structure but with coagulation of cell debris- friable, crumbly material like cottage cheese
liquefactive necrosis
cell death with loss of cell structure and reduction of cell debris by proteolysis to a liquid soup of small molecs
transudate
watery fluid accumulating in tissues- usually the result of increased hydrostatic pressure or low plasma osmolarity
exudate
fluid accumulation in tissue due to incr. vascular permeability. high protein content; usually accompanied by inflam. cells
chemotaxis
locomotion directed along a chemical gradient
What are the 5 cardinal signs of inflammation>
redness, heat, swelling, pain, loss of function
Why are fluids important in terms of inflammation?
easier passage of cells through the ECM
carries plasma proteins to the site of injury
dilutes toxins/chemical mediators of inflammation
neutrophils: what kind of inflammation? what do they do? Time scale?
primary effector cells of acute inflammation
engulfment and destruction of bacteria and cell debris
predominate 24-48 hrs, then apoptose and replaced by macrophages
may continue to predominate in some infections
monocyte/macrophages: what kind of inflammation? time scale? what do they do? how are they different from each other?
predominant cells of chronic inflammation
seen in larger numbers 48-72 hrs after acute infections and from the start in primary chronic infections
engulf and destroy invaders and cell debris bu also activate and present antigens to the lymphocytes
orchestrate cell mediated/humoral immunity
monocytes differentiate in the tissues into macrophages
lymphocytes: what kind of inflammation? What do they do?
chronic inflammation
cell-mediated cytotoxicity, stimulate and are stimulated by macrophages, make INs and IFNs. T and B cells are effectors of the humoral response.
Eosinophils: what kind of inflammation? What do they do?
chronic inflammation, esp. against parasitic infection
secrete major basic protein= toxic to parasites (and also many host cells)
Basophils/Mast cells: what do they do?
produce histamine and other vascular response mediators. can produce proinflammatory cytokines in chronic inflammation
Fibroblasts: inflammation type; role
chronic inflam
proliferate to initiate the repair process
produce collagen to aid in wound closure, scar formation, and wall of granulomas/mature abscesses
Acute inflammation: goals, factors involved
gaol: be fast, destroy/remove invaders or damaged tissues, and then disappear to allow healing.
accomplished by RAPID VASCULAR CHANGES to allow neutrophils, plasma proteins, and water access
acute inflammation: what is needed?
BLOOD SUPPLY
this is a VASCULAR process
in avascular or dead tissue, acute inflammation will not occur or occurs only at the periphery
What cells are the hallmark of acute inflammation?
neutrophils
efficient phagocytes that can destro bacteria and in small amts necrotic tissue
apoptose after 48-72 hrs
What happens during the process of chronic inflammation (ie. goals)? When might it occur?
prolonged inflammatory response to continued tissue injury where the removal of invaders or injured tissue occurs simultaneously with attempts at tissue repair
may follow prolonged acute inflammation or may be a primary response to some injuries
What kind of response is chronic inflammation? What is the hallmark cell? What are important features of how that cell gets to site of inflammation?
cellular response
macrophage
more can be reruited through the influx of monocytes from circulation, which turn into macrophages. macrophages can proliferate in tissue via cell division.
What is granulomatous inflammation?
aggregation of epithelioid macrophages surrounded by a a collar of lymphocytes. may have central necrosis, which may be either liquefactive or caseous
What are epithelioid macrophages?
transformed macrophages with a pale pink finely granular cytoplasm and indistinct cell boundries on H&E stains. only happen in conjunction with T-cell mediated immunity since gamma ifn is needed for macrophage transformation
What organisms/diseases predispose to granulomatous inflammation?
M. tuberculosis, M. leprae, sarcoidosis, foreign bodies trapped in tissues
