acute inflammation Flashcards
what is acute inflammation of the gingival tissue?
gingivitis
what are the 3 main processes involved in acute inflammation?
- vascular dilation
- increased vascular permeability
- neutrophil activation and migration
what is acute inflammation a response to?
response of living tissue to infection/damage
what kind of immunity is associated with acute inflammation?
initiation of innate immunity
what are the 4 main causes of acute inflammation?
microbial infection
physical agents
irritant and corrosive chemicals
tissue necrosis
how does microbial infection cause acute inflammation?
resulting from microbial recognition
what are physical agents that can cause acute inflammation?
physical trauma
ultraviolet or other ionising radiation
heat
cold
what irritants and corrosive chemicals cause acute inflammation?
acides, alkali, oxidising agents
microbial virulence factors
how does tissue necrosis cause acute inflammation?
lack of o2 or nutrients
inadequate blood flow (infarction)
what are 5 consequences of acute inflammation?
redness - rubor
heat - calor
swelling - tumour
pain - dolor
loss of function
describe redness as a consequence of acute inflammation?
dilation of small blood vessels
describe heat as a consequence of acute inflammation?
increased blood flow (hyperaemia)
describe swelling as a consequence of acute inflammation?
accumulation of fluid in extra vascular space (oedema)
describe pain as a consequence of acute inflammation?
stretching/distortion of tissues due to oedema
chemical mediators induce pain
what is oedema?
excess of watery fluid collecting in cavities or tissues of the body
in which stage of acute inflammation does chronic inflammation arise?
no resolution
what is the amplification stage in the inflammation process?
recruitment and activation of innate immune cells via chemokines and cytokines activity and vascular dilation
what is exudation?
the vessels become leaky and allow passage of water salts and some proteins
what happens in a vascular response? 3
small blood vessels dilate
endothelial cells what and retract
exudation - minerals pass out of cell
endothelial cells activated to promote immune cell passage to damaged tissues
what does inflammatory exudate provide to tissues?
fluids and salts
glucose and oxygen
complement proteins and antibodies
fibrin (long insoluble filamentous protein)
give examples of chemical mediators?
histamine
bradykinin
prostaglandins
what do chemical mediators do?
vascular dilation
increasing vascular permeability
1 more?
give examples of protein mediators?
cytokines and chemokines
what is the function of mediators?
regulate process of inflammation
what is the product of the break down of histidine (amino acid)?
histamine
where is histamine stored?
granules of immune cells such as mast cells
how is histamine released?
degranulation
how does histamine has a role as a neurotransmitter?
itching
what does histamine cause?
vascular dilation
what produces prostaglandins? what are they the product of?
macrophages and neutrophils (with leukotrienes)
- product of fast acid metabolism
what is the most abundant prostaglandin?
prostaglandin E2 (PGE2)
what do prostaglandins cause?
vascular dilation
what are the other roles prostaglandins in acute inflammation?
- regulate cytokine production
- regulate cell recruitment
- act on nerve fibres (pain)
- involved in tissue remodelling
what enzyme regulates prostaglandins?
cylooxygenase II
what characterises inflammation? 3
changes in blood vessel caliber
vascular permeability
oedema (protein and cellular exudates )
what are blood vessel changes regulated by?
protein and chemical mediators
what are the 4 proteolytic cascades of plasma factors in acute inflammation?
complement
kinin system
coagulation
fibrinolytic system
how are the proteolytic cascades of plasma factors initiated in acute inflammation?
stepwise activation involving formation of enzyme complexes and protein cleavage
what enzyme activates the proteolytic cascades of plasma factors?
coagulation factor XII
how is kallikrein generated?
by hageman factor (coagulation factor XIIa)
what does kallikrein do?
converts kininogens to kinins eg. bradykinin
what are the 3 pathways of the coagulation system?
intrinsic
extrinsic
common
what happens in the common pathway of the coagulation system?
production of thrombin which produces fibrin (clot formation)
what happens in the kinin cascade in plasma factor?
plasma protein/enzymes that lead to production of bradykinins
what happens in the complement cascade in plasma factors?
leads to membrane attack complex formation and anaphylatoxin production
what does fibrin do in the coagulation cascade in plasma factors?
stable blood clot formation (fibrin)
what is the main aim of the fibrinolytic system?
activation of plasmin which prevents excessive clotting of blood by degrading fibrin
what do kallikrein and hangman factor both play a role in, in the fibrinolytic system ?
conversion
how does the fibrinolytic system play a role as fibrin degradation products?
promotes vascular permeability
what is haemostasis?
balance between coagulation and fibrinolytic system
what does haemostasis mean?
stop of blood flow
give examples of congenital coagulation disorders?
- von willebrand disease
- haemophilia A
- haemophilia B
give examples of acquired coagulation disorders? eg. drugs
warfarin
heparin
what does abscess formation (suppuration) lead to?
chronic inflammation
what does abscess formation depend on?
- tissues involved
- amount of tissue destruction
- nature of the harmful agent
name the 3 types of dental abscesses?
gingival abscess
periodontal abscess
periapical abscess
what is suppuration?
formation of puss arising from infection (abscess)
what is the most important part of suppuration?
neutrophil infiltration
what is pus?
bacteria with dead and dying neutrophils
what is pus surrounded by once it accumulated?
pyogenic membrane
what does the complete restoration of tissues after an episode of acute inflammation require?
- minimal cell death and tissue damage
- occurrence in tissues with regenerative capacity
- rapid elimination of causative agent
- rapid removal of debris by vascular/lymphatic drainage
what is the end goal of acute inflammation?
healing and repair
what is the most common outcome of acute inflammation?
resolution