Acute Inflammation 1 Flashcards
What tissue does inflam occur
In vascularised ue
What does inflam aim to do
Destroy dilute wall off injurious agent
What kind of repsonse is inflammation
Primarily protectionn
What would happen without inflammation
Woudns wouldn’t heal
Injured organs might remain permanet festering sores
Infectious Wouk,d go unchecked
How can inflammation be harmful
Life threatening hypersensitivity
Chronic hi diseases (rheumatoid arthritis)
Renoir by fibrosis lead to disfiguring scars
What are the two types of inflammation
Acute and chornic
What’s is acute inflammation
The initial and often transient serious of tissue reactions to injury
What su chronic inflammation
The subsequent and often prolonged tissue reactions following initial response
What can cause acute inflam
Microbial infections - viruses, bac
Hypersensitivity reactions - inappropriate or excessive immune reaction which damages tissue incl parasites
Physical agents - physical trauma
Irritant or corrosive chess
Foreign bodies
Why does inflam have redness
Rub or acutely inflames tissue is red as blood vessels dilated in damaged area
Why is inflam heat
Increase temp of tissue due to increased blood flow through region hyperaemia
Why does inflammation swell
Tumor
Results form accumulation of fluid in extravascylar space - fluid exudate
Why is there pain with inflam
Dollar
Due to stretching and distortion of tissues caused by increased fluids - various chem mediators including bradykinin known to prod pain
Why dos inflam cause loss of function
Movement of inflame area is consciously and reflexly inhib by pain
Severe pain may immobilise limbs
Explain the vascular phase
Vascular dilation opening of precap sphincter
Also endothelial cells lining arterioles increased perm and form flid exudate
What is the net increase in extravascylar fluid called
Oedema
What is in fluid exudate and why
Immunoglobulins -imp for destruction of foreign bodies
Fibrinogen - becomes fibrin when comes in contact with ECm
What continually sholens to the exudate
Removed and replaced by lymphatics and new exudate formed
What brings about incised vascular perm
Bradykinin histamine - immediate transient
Severe direct vasc injury - immediate sustained
Endothelial cell injury - delayed prolonged
What so the diagnostic feature of acute inflam
Neutrophils accumulation in ecm
What are the functions of neutrophils
Kill micoro orgas Ingest offending agents Degrade necrotic tissue Produce chem mediators Prod toxic oxygen radicals Prod tissue damaging enzymes
How does a neutrophil each the site of an inflam response
Many ways
Adhesion to leukocytes to endothelial cells and subsequent migration Thor endothelium
What is margination
Loss of intra vasc fluid and inc plasma visc slows allowing neurohils flow in plasma tic zone which Is margination
ONLY IN VENULES
What so adhesion
Increased neurohils adhesion results from between interaction of adhesion mol on its surface and endothelial surface
What is transendothelial migration
Once adhesion occurred
Neurohils insert pseudopodia into junctions between endothelial cells
Then cross base mem and into extravascylar space
What are some predominat molecules in migration
Increased selectins on endo
Loose rolling adhesion between selectins and their recep leukocyte
Firm adhesion between integrins on leucocyte and ICAM1 on endo cell
Transmigration mediated by ICAM1, integrins and PECAM1
What increases lucocyte adhesion molecule expression
Complement component ca
Leukotriene b4
Tumour necrosis factor
What increases the endothelial cell expression for adhesion of other things such as neutrophils and other leukocytes
IL1
Endotoxins
Tumour Necrosis factor
How do neurohils find site of inflam stimulus
By chemo taxis - locomotion orientated along conc grad
What are chemotactic compounds for neutrophils
Bac prods
Complement comps
Cytokines
Products produced by neutrophils themselves
What happens when chemotactic agent attaches to neutrophil
Release for intracellular calcium
Influx of extracellular calcium
What does increased cytosol if calcium tigger
Assembly of contractile proteins responsible for cell movement
What are the chemical be released form the inflam site called
Endogenous
What can these endogenous chms cause
Vasodilation Emigration of neutrophils Chemotaxis Increased vasc perm Itching and pain
What does histamine do for inflammation
Vasc dilation
Transient inc in vasc perm
Released by mast cells, eosinophils, basophils and platelets
Release stim by c3a c5a and lysosomal proteins
How do lysosomal compounds affect inflammation
Released form neurohils
May increase vasc perm
What does serotonin do for inflam
Inc vasc perm
What doe chemekines do in inflam
Proteins which attacks of leucocyte to sit of inflam
Various chemekines bind to scm component setting up a gradient of chemotactic mols fixed to ECm
What do leukotripenes do in inflam
Syn by arachnoid acid especially by neurohils
Vasoactive properties
Involved in type 1 hypersensitivity
What do prostaglandins do in inflam
Fatty acid syn
Inc vasc perm
Stim platelet aggregation
Plasma contains what four enzyme cascades which mediate aspects of inflam in addition to other factors
Complement syst
Kinin syst
Coagulation syst
Fibrinolytic system
What causes complement activation
Enzymes released form dying cells
Antigen-antibody complexes
Products of kin in, coag and fibrinolytic systems
Bac endotoxins
What hallens as a result of complement activation
Opsonisation of pathogens (phagocytosis)
Increase vasc perm
Recruit inflam cells
Histamine see lease from mast cells vasodilation
What does the kinin syst gen
Vasoactive peptides form plasma proteins called kininogens by action of specific kallikreins
What activates the kinin syst
Coag factor 12 leads to form of kinins such as bradykinin
What’s does bradykinin cause
Increased vasc perm
Arteriolar dilatation
Smooth muscle contraction
Pain
What does the coag system do
Conversion of fibrinogen into fibrin
What is fibrin
Component of acute inflam infiltrate
What dos the fibrinolytic syst do
Counterbalance coag syst as plasminogen activators cleave plasminogen to give plasmin
What is plasmin responsible for
Lysis of fibrin into fibrin degradation prods which increase vasc perm
What’s inflammation. A response to
Tissue injury
