Block E Lecture 1: Hypersensitivity Flashcards
What is inflammation?
A biological response of the innate immune system
(Slide 3)
What 3 ways can inflammation be triggered?
Pathogens
Damaged cells
Toxin compounds
(Slide 3)
What are the 5 classic signs of inflammation?
Heat
Redness
Swelling
Pain
Loss of function
(Slide 4)
What causes the heat and redness signs of inflammation?
High blood flow heating the tissue and causing redness caused by increased blood flow and capillary widening (vasodilation)
(Slide 5)
What causes the swelling sign of inflammation?
Fluid released into tissues, increased permeability and tenderness due to an increased influx of leukocytes to the site of injury
(Slide 5)
What causes the pain sign of inflammation?
Fever and proliferation of leukocytes
(Slide 5)
What causes the loss of function sign of inflammation?
Resolution, wound healing and scar tissue preventing movement
(Slide 5)
When does the inflammatory response start?
When macrophages and other cells residues in the affected tissues are activated
(Slide 6)
How are macrophages and other cells resident in affect tissues needed to start the inflammatory response activated?
By PAMPS and DAMPS to PRRs
(Slide 6)
What are 4 inflammatory mediators?
Leukotrienes
Prostaglandins
Platelet activating factors
Histamine
(Slide 6)
What do inflammatory signals secreted by injured tissue (endothelial cells), mast cells and macrophages induce?
Vascular changes
(Slide 7)
What are 3 examples of the vascular changes caused by inflammatory mediators secreted by injured tissue, mast cells and macrophages and what do these changes each do?
Increased blood flow to area - increasing deliver of beneficial proteins / leukocytes
Increased vascular permeability - allowing plasma proteins to gain entry to interstitial fluid (body fluid between blood and cells)
Complement (C5a) enhancing the process of vasodilation and helping activate endothelial and mast cells resident in tissues
(Slide 7)
Can dendritic cells and macrophages phagocytise bacteria?
Yes
(Slide 9)
What 4 cells are the key cellular components of inflammation?
Neutrophils
Macrophages
Dendritic cells
Mast cells
(Slide 9)
What do phagocytes do once they enter the area of infection and encounter microbes?
They release inflammatory mediators that bring in even more phagocytes
(Slide 11)
What may the inflammatory mediators released by phagocytes induce?
Fever
(Slide 11)
What is considered fever in humans?
A body temperature greater than 38°C (100.4°F)
(Slide 11)
What 4 things does fever do?
Stimulate leukocyte activity
Provide a less hospitable environment for some pathogens
Destroys / inactivates pathogens
Clears area of dead cells, setting the stage for tissue repair
(Slide 11)
What is extravasation of leukocytes highly regulated by?
Adhesion molecules
(Notes section of Slide 12)
What 2 things can occurs when the immune system’s strategies to reduce damage to self fail?
Auto-immunity and Hypersensitivity
(Slide 14)