Flashcards in Inflammation and Healing Deck (94)
local tissue response to injury
name some beneficial effects of inflammation
Destruction of invading microorganisms.
Walling off of an abscess cavity - preventing spread of infection.
give examples of how inflammation may cause disease
An abscess in brain = space-occupying lesion, compressing surrounding structure.
Fibrosis from chronic inflammation - distort tissues, alter function.
define acute inflammation
the initial and often transient series of tissue reactions to injury
define chronic inflammation
subsequent and often prolonged tissue reactions following the initial response
what type of cell is characteristically recruited in acute inflammation?
list the possible outcomes of acute inflammation
suppuration (e.g. abscess)
progression to chronic inflammation
what is the vascular component of acute inflammation?
dilatation of vessels
what is the exudative component of acute inflammation?
vascular leakage of protein-rich fluid
list the causes of acute inflammation
tissue necrosis (e.g. ischaemic infarction)
name some physical agents that may cause acute inflammation
trauma; ionising radiation; heat; cold
name some chemical agents that may cause acute inflammation
corrosives; acids; alkalis; reducing agents
describe how a microbial infection causes acute inflammation
viruses - death of individual cells by intracellular multiplication.
bacteria - release of exotoxins/endotoxins
how does a hypersensitivity reaction cause acute inflammation?
inappropriate/excessive immune reaction damages tissues
define tissue necrosis
death of tissues from lack of oxygen/nutrients resulting from inadequate blood flow (infarction)
what are the macroscopic appearances of acute inflammation?
redness - rubor
heat - calor
swelling - tumor
pain - dolor
loss of function
what causes redness/rubor in acute inflammation?
dilatation of small blood vessels within the damaged area
what causes the heat associated with inflammation of peripheral parts of the body?
increased blood flow (hyperaemia) through the region - vascular dilatation and delivery of warm blood
what causes swelling associated with acute inflammation?
oedema - accumulation of fluid in extravascular space as part of fluid exudate.
also physical mass of inflammatory cells.
what causes the pain associated with acute inflammation?
stretching/distortion of tissues due to oedema.
pus under pressure in an abscess cavity.
chemical mediators (bradykinin, prostaglandins, serotonin)
what causes loss of function in acute inflammation?
movement of inflamed area is consciously and reflexly inhibited by pain.
severe swelling may limit movement.
If there are neutrophil polymorph's present, is it acute or chronic inflammation?
what are the three processes involved in acute inflammation?
1. changes in vessel calibre and flow
2. increased vascular permeability and formation of fluid exudate
3. formation of cellular exudate - migration of neutrophil polymorphs into extravascular space
describe the changes in vessel calibre seen in acute inflammation
dilatation of arteriole
opening of pre-capillary sphincter
most capillaries full of blood
give some examples of chemical mediators that increase vascular permeability in acute inflammation?
what is exudation?
net escape of protein-rich fluid from blood vessels
what proteins are present in the fluid exudate seen in inflammation?
coagulation factors - fibrin deposition
describe the process of neutrophil polymorph migration into tissues in acute inflammation
1. margination of neutrophils
2. pavementing of neutrophils
3. pass between endothelial cells
4. pass through basal lamina and migrate into adventitia
what is the main source of histamine?
mast cells, stored in granules in their cytoplasm