what are the 5 signs of acute inflammation
- heat -from hyperaemia
- redness - from hyperaemia
- swelling - edema
- pain - bradykinin from inflammatory response
- loss of function -doesnt always happen
Name and describe the various levels of severity in inflammation
- minimal - can only be seen histologically
- mild - small amount of damage, low amount of hyperaemia and edema with little to no tissue destruction
- moderate - more obvious signs of inflammation with tissue destruction but it is not life threatening and doesn’t effect organ function
- severe - lots of tissue damage with a lot of exudate. can be life threatening and compromises organ function
NOTE: this is subjective!
what are some clues to tell you the duration of inflammation
-presence of hyperaemia, fibrin and fibrosis
name and describe the various duration stages of inflammation
-peracute: a few hours after, caused by potent stimulus - just happened! there will be edema, hyperaemia, hemorrhage with only a few leukocytes
-acute: within 4-6 hours and lasts 3-4 days. hyperaemia, warmth, swelling, pain, hemorrhage, exudation of fibrin and neutrophils.
-subacute: a few days (3-4d), gradual decline in edema and hyperaemia, and mixed neutrophilic and mononuclear cells (macrophages and plasma cells)
-chronic: persistant stimulus that host is unable to eliminate. macrophages and lymphocytes and plasma cells present. tissue repair processes like angiogenesis and fibroplasia
and fibrosis (scarring)!!
-chronic-active: has both chronic inflammatory characteristics (mononuclear cells and fibrosis) and acute characteristics(neutrophils, fibrinous exudate). long standing inflammation that continues to progress
what is the difference between fibrinogen and fibrosis?
- fibrin comes out early in inflammatory process (acute) and is easily peeled away (serosal tissue)
- fibrosis is chronic indicator and is unable to be peeled off of the organ (serosal tissue)
what are 4 terms to describe the distribution of inflammation
- focal
- multifocal
- diffuse
- locally extensive
Name 3 types of exudate?
- serous exudate
- fibrinous exudate
- suppurative exudate
describe serous exudate
- fluid that is transparent, yellow and uncoagulated
- on serosal surfaces
- result from serum that has leaked out of the blood vessels
describe fibrinous exudate
-fibrinogen that have leaked out of the endothelial cells because of damage to endothelial cells causing greater vascular permeability. this forms fibrin and is deposited in the extracellular space and body cavity
describe the gross morphology of fibrinous exudate within: serosal surfaces, lungs, mucosal surfaces, joints and ocular chamber.
Also, microscopic morphology
- serosal surface: if small amount then looks like ground glass but if large amount then yellow, soft, elastic and friable material on the surface
- lungs: yellow-red inter lobar and intraalverolar exudate in lungs causing firmness in pulmonary tissue
- mucosal surfaces: membrane has fibrin and sloughed necrotic epithelium that is weakly attached to eroded mucosa underneath
- joints: white-yellow friable material floating in the synovial fluid
- ocular chamber: floating white flakes
- micro: eosinophilic meshwork of threads
What are two outcomes of fibrinous exudate?
- it is removed by fibrinolysis and cleared by macrophages - resulting in resolution
- it is not removed and may stimulate ingrowth of fibroblasts and blood vessels resulting in scarring
what is fibrinosupperative/fibrinopurluent exudate?
when fibrinous exudate is mixed with neutrophils
what is fibrinonecrotic exudate?
when fibrinous exudate is mixed with necrotic tissues
describe suppurative exudate
-production of a large amount of pus exudate consisting of neutrophils, necrotic cells, edema fluid and usually bacteria
describe the gross and microscopic morphology of suppurative exudate
- grossly it is opaque, creamy fluid (pus) within the tissue or cavity (note: it is difficult to determine the duration unless it is surrounded by a fibrotic capsule - then chronic)
- microscopically it is homogenous, disintegrated and liquified necrotic tissues and neutrophils
What is the diagnostic significance of suppurative exudate
- presence of neutrophils show that it is acute or chronically active
- it is normally caused by bacteria
how does an abcess appear when the neutrophils are unable to kill the bacteria in a suppurative exudate?
-the capsule will the fairly thin or there will be onion ring formation because the fibrous capsule keeps trying to get the bacteria under control and contain them but is overwhelmed
name some other types of exudates
- hemorrhagic inflammation: peracute/acute inflammation with vascular necrosis
- mucoid: inflammation on mucous membranes
- non-suppurative inflammation: movement of mononuclear entering the inflammatory response
describe granulomatous inflammation
- a chronic inflammatory reaction that involves focal accumulation of activated macrophages (not neutrophils) and results in an epithelia appearance with or without necrosis
- there is often giant cells, macrophages, lymphocytes that surround neutrophils and the ceaseous necrosis. all of these cells are surrounded by a fibrous ring
- often unable to distinguish between granuloma and neoplasm grossly
