Acute inflammation 1-2 Flashcards
Acute inflammation
Basic response which sorts out vertebrates and protects tissue in response to injury
Rubor
redness
Tumour
swelling
Calor
Heat
Dolor
pain
Causes/aetiology
- Microorganism (bacteria, fungi, parasite, virus)
- Mechanical (trauma or injury)
- Chemical ( upset environment pH, bile, urine)
- Physical ( Heat, cold, radiation)
- Dead tissue ( necrosis)
- Hypersensitivity
Exudate
Fluid rich in protein including Ig and fibrinogen
Oedema formation ( fluid in extravascular space)
Change in permeability of vessel wall
Triple response
1 - Flush, transient arteriolar constriction
2 - Flare, local dilation - active hyperaemia
3 - Wheal, relax smooth muscle
Stasis
Rate of flow slows - change in flow characteristics
Increased permeability
Plasma from capillaries to extravascular space
Normal laminar flow
WBC - RBC - PLASMA
Flow in inflammation
WBC pushed to endothelium and RBC congregate in the centre ( rouleax formation)
Marginated neutrophils
Neutrophils move to near endothelium
Pavementing
Neutrophils adhere to the endothelium
Emigration
Neutrophils squeeze between endothelial cells
Diapedesis
RBC squeezed out of vessel and go anywhere
Resolution of acute inflammation
Agent isolated and destroyed
Macrophage from blood move in and phagocytose debris
Exudate filtered and regenerate epithelial surface
Vascular change to normal - Resolution
What do neutrophils do for macrophage
Destroy organism and denature antigen for macrophage
What part do plasma proteins play
Localise the response
4 Outcomes of acute inflammation
- Resolution
- Suppuration
- Organisation
- Chronic Inflammation
What are neutrophils job (4)
- Mobile and adhere to organism by chemotaxis
- Granules posses oxidants and enzymes
- Phagocytose and destroy foreign bodies
- Die after granule response ==> Pus formed
Fibrinogen
Coagulation factor which forms fibrin and clots exudate
Immunoglobulin
Specific for antigen and involved in humoral immune response
3 mediators of acute inflammation
Molecules on endothelial cell surface
Molecules released from cells eg histamine, serotonin
Molecules in the plasma
Effects of mediators
- vasodilation
- pain
- itch
- chemotaxis
- increased permeability
- neutrophil adhesion eg p selectin
Histamine
Released by IgE mediated reactions causing increased permeability and vasodilation and preformed in mast cells
Serotonin
Preformed in platelets - released when these degranulate and cause vasoconstriction
Prostaglandins
Promote histamine effects
Plasma 4 cascades
- Complement - inflammation and immune system link
- Kinin system - bradykinin = pain
- Fibrinolysis - breaks down fibrin
- Blood coagulation - clots fibrinogen in exudate
Suppuration - pus formation
Dead tissue, exudate, neutrophil, fibrin, red cells surrounded by a pyogenic membrane
Abscess
Collection of pus under pressure and can be single or multi loculated - burst through pyogenic membrane
Empysema
Pus in other places - hollow, delocalised area
Pyaemia
Discharge of Pus in the blood
Organisation
Granulation tissue - heal and repair
Fibrosis = scar formation
4 things needed for repair
Angiogenesis, collagen + fibroblast and macrophage
Bacteraemia
Bacteria in the blood
Septicaemia
Growth of bacteria in the blood
Toxeamia
Toxin production in the blood
