Acute and Chronic inflammation Flashcards
What is acute inflammation?
Response of living tissue to infection/damage
Develops quickly
Initiation for innate immunity
What are the three processes involved in acute inflammation?
Vascular dilation
Increased vascular permeability
Neutrophil activation and migration
What are the four main causes of acute inflammation?
Microbial infection
Resulting from microbial recognition Physical agents, Physical trauma
Ultraviolet or other ionizing radiation, Heat (burns), Cold
Irritant and corrosive chemicals
Acids, alkali, oxidizing agents
Microbial virulence factors
Tissue necrosis
Lack of oxygen or nutrients
Inadequate blood flow (infarction)
What are the consequences of acute inflammation?
Redness (rubor)
Dilation of small blood vessels
Heat (calor)
Increased blood flow (hyperaemia)
Swelling (tumor)
Accumulation of fluid in extra vascular space (oedema)
Pain (dolor)
Stretching/distortion of tissues due to oedema.
Chemical mediators induce pain
Loss of function
what is an example of acute inflamation?
gingivitis
What is meant by amplification?
recruitment and activation of innate immune cells via chemokine/cytokine activity and vascular dilation
what is the vascular response to acute inflammation?
Small blood vessels adjacent to site of damage become dilated
Endothelial cells swell and retract
Exudation – the vessels become ‘leaky’ and allow passage of water, salts and some proteins
Endothelial cells activated to promote immune cells passage to damaged tissues
What is oedema?
defined as excess of watery fluid collecting in the cavities or tissues of the body.
increased blood and lymph flow.
in tissues what allows for the diffusuion of mediators?
salt and fluids
Give 3 examples of mediators involved in inflammation
chemical- Histamine
Bradykinin
Leukotrienes
Serotonin
Prostaglandins
Protein- cytokines, chemokines
Describe and explain histamines role here?
Product of breakdown of amino acid histidine
Stored in granules of immune cells such as mast cells
Degranulation releases histamine
Role as a neurotransmitter – itching
Causes vascular dilation
Many immune cells express histamine receptors
Describe prostaglandins and explain their role.
Produced by macrophages and neutrophils (with leukotrienes)
Product of fatty acid metabolism
Most abundant is Prostaglandin E2 (PGE2)
Causes vascular dilation
other roles- Regulate cytokine production
Regulate cell recruitment
Act on nerve fibres – pain
Involved in tissue remodeling
What are the 4 enzymatic cascades?
Complement (covered in innate immunity II)
The kinin system
Coagulation
Fibrinolytic system
describe a complement cascade?
3 pathways
Classical pathway – antibody attached to microbe
(2) Alternative pathway – microbial cell wall
(3) Mannose binding lectin pathway (MBL) – carbohydrates on pathogen surface
what is generated by Hageman factor?
Kallikrein
In the kinin system what does Kallikrein convert?
Kallikrein converts kininogens to kinins (e.g., bradykinin)
what do all three pathways of the coagulation system result in?
Production of thrombin which in turn produces fibrin (clot formation)
intrinsic and extrinsic
What does the fibrinolytic system result in?
activation of plasmin
What is involved in the fibrinolytic system?
invokved in blood clots
The balance between which two systems is essential for homeostasis?
Coagulation and fibrinolytic
Acute inflammation leads to what that chronic doesn’t?
resolution
Absess formation (suppuration) is an outcome of what?
acute inflammation
3 types of gingival absesses?
Gingival abscess
Periodontal abscess
Periapical abscess
What is the difference between acute and chronic inflammation?
accute- rapid (days)
chronic inflammation persistent can occur over months, years
