Accute Inflammation Flashcards
What is acute inflammation
- response of living tissue to infection/damage
- develops quickly
- initiation for innate immunity
What are the three main processes involved in inflammation
- vascular dilation
- increased vascular permeability
- neutrophil activation and migration
What are the main causes of acute inflammation
- microbial infections
- physical agents
- irritant and corrosive chemicals
- tissue necrosis
What are some consequences of acute inflammation
- redness (rubor)
- heat (calor)
- pain (Dolor)
- loss of function
- swelling (tumor)
What is hyperaemia
Increased blood flow
What is oedema
Accumulation of fluid in extra vascular space
Describe acute inflammation in gingivitis
Initiation - microbes in dental plaque recognised by gingival epithelial cells via pattern recognition receptors
Progression - containment of microbes by innate immune cells and Antimicrobial compounds
Amplification - recruitment and activation of innate immune cells via chemokine/cytokine activity and vascular dilation
Resolution - healing and repair
No resolution - progression to periodontitis
Describe amplification in gingivitis
Bacteria trigger macrophages to release cytokines and chemokines
Vasodilation and increased vascular permeability cause redness, swelling and heat
Inflammatory cells migrate into tissues releasing inflammatory mediators that cause pain
What are vascular responses to acute inflammation
- small blood vessels become dilated
- endothelial cells sweat and retract
- exudation - vessels become leaky and allow passage of water, salts and some proteins
What is an oedema
Defined as an excess of watery fluid collecting in cavities or tissues in the body
Inflammatory exudate provides the following to tissue…
- fluid and salts
- glucose and oxygen
- complement proteins and antibodies
- fibrin
Name some chemical mediators
- histamine
- bradykinin
- leukotrienes
- serotonin
- prostaglandins
Name protein mediators
- cytokines
- chemokines
What is the role of histamine
- role as a neurotransmitter - itching
- causes vascular dilation
What are prostaglandins
- produced by macrophages and neutrophils
- product of fatty acid metabolism
What is the role of prostaglandins
- causes vascular dilation
Multiple other roles in acute inflammation
- regulate cytokine production
- regulate cell recruitment
- act on nerve fibres
- involved in tissue remodelling
What plasma factors are involved in acute inflammation
- 4 proteolytic cascades
- complement
- the kinin system
- coagulation
- fibrinolytic system
What enzyme does ibroprofen target
Cyclo-ocygenase II
What are the three complement pathways
- classical pathway
- alternative pathway
- mannose binding lectin pathway (MBL)
Describe the Kinin system
- involves a number of plasma proteins/enzymes
- kallikrein is generated by hagemen factor
- neutrophils also engage in this system
- kallikrein converts kininogens to kinins
What are the three pathways of the coagulation system
- intrinsic
- extrinsic
- common
Describe the intrinsic pathway
Activates when the blood comes into contact with the sub endothelial connective tissue (outside blood vessel)
Describe the extrinsic factor
Damaged blood vessel means Human factor VII leaves vessel and encounters tissue factor in the surrounding tissue
Describe the common pathway
Production of thrombin which in turn produces fibrin
Describe the fibrinolytic system
- results in the activation of plasmid
- kallikrein and hageman factor
- prevents excess clotting in health
- activates complement
- indirect role as fibrin degradation products promotes vascular permeability
Name some congenital coagulation disorder
- Von willebrand disease
- haemophilia A and B
What are acquired coagulation disorders (drugs)
- warfarin
- heparin
What pathway is used to form a blood clot
Fibrinolytic system
What pathway leads to membrane attack complex formation and anaphylatoxin production
The kinnin system
What pathway leads to production of Bradykinins
Coagulations
What are the three types of dental abscess
- gingival abscess
- periodontal abscess
- periapical abscess
Describe suppuration
Formation of pus arising fro an infections
What is pus
Bacteria with dead and dying neutrophils
What is the most common outcome of acute inflammation
Resolution
What produces histamine
Mast cells
Histamine causes…
Vascular dilation
Bradykinin is involved in…
Coagulation cascade
What is the role of serotonin
Produced by nerve cells, acts as a chemoattractant
What mediators regulate the process of inflammation
- histamine
- bradykinin
- prostaglandins
What is histamine a product of
The breakdown of amino acid histidine
What is the most abundant prostaglandin
Prostaglandin E2 (PGE2)
Describe the process of prostaglandin being released
Stimulation of cells by TLR activation (microbial recognition) leads to activation of cyclo-ocygenase II(COX II), leads to prostaglandin being released
What do non steroidal inflammatory drugs target
They target COX enzyme to block the release of prostaglandins therefore inflammation, pain and fever are reduced
Give two examples of mediators that regulate blood vessel changes
Histamine and prostaglandins
What role do plasma factors play in innate immunity
- cytokine signalling, the complement system, acute phrase response
What is the role of kallikrein
Converts kininogens to kinins (eg bradykinin)
What is the role of bradykinin
Similar to histamine
- activates complement
- increases vascular permeability
- stimulates nerve pain
- induces expression of cytokines and chemokines
- induce production of chemical mediators
What is the final outcome of coagulation pathways
Clot formation
What is the role of warfarin
Anti coagulant, inhibits coagulation factors
What is an outcome of acute inflammation that can lead to chronic inflammation
Abscess
What is a gingival abscess
Formed due to infection or trauma to the surface of the gum tissue
What is a Peridontal abscess
Forms due to infection yay as moved deeper into the gum areas
What is a periapical abscess
Due to infection of the pulp
What is suppuration
Formation of pus
What is pus
bacteria with dead and dying neutrophils
The complete restoration of tissues after acute inflammation requires…
- minimal cell death and tissue damage
- occurrence in tissues with regenerative capacity
- rapid elimination of causative agent
- rapid removal of fluid and debris by vascular/lymphatic drainage
