Acute and Chronic Inflammation Flashcards
Definition of inflammation
Reaction of vascularized living tissue to local injury. In higher animals, reaction of blood vessels to local injury leads to the accumulation of fluid and cells that characterize inflammation
Definition of repair
The replacement of injured tissue either by regeneration of damaged parenchyma can divide and be replaced or by fibroblastic/glial scar tissue
Definition of stereotypic
The course of reaction is the same irrespective of the cause of inflammation
Definition of exudate
Inflammatory extravascular fluid with increased [protein], cellular debris and SG above 1020
Definition of pus
Purulent exudate rich in neutrophils and parenchymal cell debris
Definition of margination
Increased adhesion of inflammatory cells to endothelium and rolling along endothelium
Definition of chemotaxis
Unidirectional migration of cells towards a chemokine
Definition of diapedesis
Movement across endothelium into the tissue
Definition of extravasation
Movement of cells into tissues following the chemokine gradient
Definition of suppurative inflammation
Accumulation of pus is the main feature in inflammation
Definition of granuloma
Macrophages with a cuff of lymphocytes
What are the properties of an acute inflammatory response Associated with what immune response Cells associated with response Timeframe Type of reaction
Innate
Neutrophil polymorphs
Up to 2 days, rapid onset and resolution
Stereotypical
What are the properties of a chronic inflammatory response Associated with what immune response Cells associated with response Timeframe Type of reaction
Adaptive
Macrophages, lymphocytes, mononuclear cells
2 days - decades
Multifactorial => proliferation of BV and connective tissue
Describe inflammation
What tissues don’t get inflamed
Reaction of vascularized living tissue to local injury
Non vascular tissues (cornea) don’t get inflamed according to the classical definitions
Describe the 3 step pathway of acute inflammation
Normally neutrophils only express adhesion molecules
Histamine, C5a, LPS cause Weibel Palade bodies to release P selectin
E selectin produced by endothelium due to cytokines
Neutrophils marginate, ICAM interaction => firmer connection
Permits diapedesis, extravasation due to bacterial components, C5a, leukotriene B4 in dead/damaged cells, chemokine (IL8)
What 3 vascular changes => 4 cardinal signs
Transient VC of arterioles => prolonged VD => RUBOR, CALOR due to increased flow
Permeability of endothelium increases in capillaries, venues => TUMOR, DOLOR due to edema stretching cutaneous nerves
Circulation slows => stasis possible
What are the 4 types of acute inflammation
Serous
- v few cells present, fluid accumulation
- Burns, friction blister
Suppurative
-Neutrophils involved
Fibrinous
-Fibrin involved
Membranous
- Inflammatory membrane forms
- Cdiff, diphtheria
What are the 2 typical features of acute inflammation
Exudate
- inflammatory extravascular fluid
- high protein, cell debris
Pus
-Purulent exudate rich in neutrophils and cell debris
What is chronic inflammation
What is it characterised by
Can follow acute inflammation/persistent infection or exposure to non degradable substances
Infiltrated by macrophages, lymphocytes, plasma cells, fibroblasts, blood vessels
What are the 3 types of chronic granulomatous inflammation
All involve
- macrophages attracted via chemokine => granuloma
- Loses cytoplasmic volume => look like epithelial cells
- Fibroblasts produce collagen and replace granuloma with fibrous scar
Caseating is the same as non caveating except
-Necrosis is amorphous, featureless
Foreign body
-Macrophages fuse together => giant cell phagocytosis large foreign material
What are the results of repair
Injured tissue
- regeneration of damaged parenchyma
- fibroblastic (collagen)/glial scar tissue (astrocytes)
What are 3 examples of the negatives of inflammation and repair
Rheumatoid arthiritis
-Lymphocytes in synovium responsible for rheumatoid factor prod
Fibrous adhesions in bowel survey
-Loops of bowel heals incorrectly => bowel adhesion
Glomerular nephritis
-Immune complexes deposited in glomerulus
