Inflammation Flashcards
What are the 5 signs of inflammation?
Pain-chemicals releases at nerve endings
Redness-increased blood flow
Immobility-fluid accumulation
Swelling-fluid accumulation
Heat-increased blood flow
What are examples of acute inflammation?
*Allergic reaction
*Trauma
*Burn
*Infection
What are examples of chronic inflammation?
*CVD
*Rheumatoid arthritis
*cancer
What is the predominant cell type in acute inflammation?
Neutrophils
What occurs in the vascular stage?
*arterioles and venules near site of injury constrict briefly then dilate -cell congestion
*increased capillary permeability =fluid moves into affected tissue
*fluid leaves capillaries
*blood in circulation becomes more viscous, slow flow, clot can occur
What occurs in the cellular stage of acute inflammation?
*leukocytes (neutrophils) recruit to site-initiation
* leukos adhere to vessel wall and pass into inflamed tissue site (emigration)
*leukos move through tissue guided by chemicals- chemotaxis
*leukos engulf and degrade bacteria/debris- phagocytosis
What is chemoattraction in acute inflammation?
*macrophages release pro-inflammatory cytokines
*cytokines signal recruit leukos
*triggers endothelial cells to express adhesion molecules-selectins (p&e)
*selectins recognise glycans on cell surface of leukocytes
What is rolling in acute inflammation?
*endothelial cells express surface adhesion proteins- P&E selectins
*selectins recognise the glycoproteins and integrins expressed on leuko surface
*leuko rolls slowly along endothelial of vessel wall
(Blood flow promotes rolling)
How does stable adhesion occur acute inflammation?
*macrophages secrete chemokines-activate rolling
*integrins on leukos bind with higher affinity
*endothelium express integrin ligands (ICAM-1)
* leukos immobilised on blood vessel surface
*KEY HALLMARK OF INFLAMMATION
What is transmigration in acute inflammation?
*leukos extend pseudopodia through gaps between endothelial cells
*PECAM expressed on leukos and endothelial cells interact pulling Leuko across endothelium wall
*leuko crosses basement membrane
*leuko moves to site of injury via chemotaxis
What mediators are involved in acute inflammation?
*Histamine and serotonin- increase vessel permeability and cause dilation.
*bradykinin- increase vessel permeability and stimulate pain receptors
*fibrin strands- enable clotting, trap exudates and foreign bodies
When does chronic inflammation occur?
When causative agent in acute inflammation not resolved.
Characterised by simultaneous destruction and repair of tissue
What are the primary cells in chronic inflammation?
Macrophages and lymphocytes
*maceophages= secrete pro anti inflammatory mediators, phagocytosis
*lymphocytes= T= activate macrophages for phagocytosis B= produce antibodies to fight foreign body
What is the causative agent for damage seen in autoimmune diseases?
Activation of macrophages by t lymphocytes
What occurs during the phagocytosis process?
Macrophages
1. Entrapment/engulfment of target
2. Phagosome formation (vesicle around ingested particle)
3. Phagosome fuses with lysosome
4. Degradation of target
5. Exocytosis out of cell
