inflammation reza2003 e video
DESCRIPTION
Class1: Acute InflammationTRANSCRIPT
Dr Rezaur Rahman
Dr Rezaur Rahman
INFLAMMATION
Definition of Inflammation:Inflammation is a complex reaction in
living vascularized tissue to injurious agents leading to the exudation and accumulation of protein rich fluid and leucocytes in extravascular tissue, provided the injury does not destroy the tissue.
Reaction of vascularized tissue to injury
Accumulation of protein rich fluid and leucocytes in extravascular tissue
Purposes:A protective response to-1. to dilute, localize and destroy the
injurious agent2. to limit tissue injury3. to restore the tissue towards
normalityHarmful effect: eg, hypersensitivity
reaction
Acute Inflammation:Rapid local response of living tissue to
injuryLasts for minutes to a few daysExtravascular accumulation of protein
rich fluid and leucocytes, predominantly Neutrophils, ie, Exudative lesion
Stereotype,ie, wide variety of agents share the same basic features
Chronic Inflammation:Persists for weeks to monthsExtravascular accumulation of
Lymphocytes and MacrophagesTissue destruction and attempts to
healing by proliferation runs simultaneously, ie, Proliferative lesion
Not stereotype
Cardinal signs of Acute Inflammation
Rubor or rednessCalor or heatTumor or swellingDolor or painLoss of function(functio laesa)
Aetiology of Acute Inflammation1. Infectious agent: Bacteria, virus, fungi,
protozoa2. Immune reaction: Hypersensitivity reaction3. Trauma: blunt/penetrating4. Physical agent: eg, burn, ionizing radiation5. Foreign bodies: eg, sutures, dirt6. Chemical agent: acids, alkalies, bile7. Tissue necrosis: eg, infarcts
Events in Acute Inflammation:1.Vascular changes:• Changes in vascular flow & caliber• Increased vascular permeability(Vascular
leakage)2.Exudation of blood constituents:• Fluid Exudate• Cellular Exudate3.Changes in tissue tissue components
Vascular changes(Flow & Caliber)Vasodilation, due to-a)Histamineb)Nitric oxide,etcIncreased permeability of
microvasculatureSlowing of circulation/ Stasis, due to-a)Exudationb)Microcirculation packed with red cellc)Increased viscosity of blood
Accounts for warmth and redness
Opens microvascular beds
Increased intravascular pressure causes an early transudate (protein-poor filtrate of plasma) into interstitium (vascular permeability still not increased yet)
Movie- Vasodilation
Vascular changes(Vascular Leakage)
Vascular changes(Vascular Leakage)
Vascular changes(Vascular Leakage)
Cellular events:A) Leucocyte Extravasation1 In the limen-a)Marginationb)Rollingc)Adhesion to endothelium2 Transmigration or diapedesis across
endothelum3 ChemotaxisB) Phagocytosis
leukocytes first roll, then become activated and adhere to endothelium, thentransmigrate across the endothelium, pierce the basement membrane, and migrate
toward chemoattractants
Movie- Leucocyte Rolling
Chemotaxis:Following extravasations, leukocytes emigrate in
tissues toward the site of injury by a process called chemotaxis.
Exogenous chemo attractants:Exogenous chemo attractants: bacterial products, etc.
Endogenous chemo attractants:Endogenous chemo attractants: components of the (LTB4), cytokines, etc.
PhagocytosisRecognition and attachmentEngulfment
PhagosomePhagolysosome
killing and degradationOxydent dependent mechanism:I.H2O2-MPO-Halide systemII.Reactive Oxygen intermediates-O2- ,H2O2,
OH- Oxydent independent mechanism: killing
occur by substances of lysosomal granules- Lysozyme, Lactoferrin, BPI, Defensin
Morphological Variants:1. Suppurative or Purulent inflammation2. Fibrinous inflammation3. Serous inflammation4. Serofibrinous inflammation5. Catarrhal inflammation6. Pseudomembranous inflammation7. Acute inflammatory ulcer8. Haemorrhagic inflammation9. Necrotizing inflammation
Movie- Inflammation
Thank You