Inflammation Flashcards
What is inflammation?
INTRO
protective biological process designed to remove damaged cells + clear threats such as infections and toxins
What cells does inflammation involve?
not only cells at the site of damage but also the recruitment immune cells, fluid and molecular components from the circulation
How is inflammation initiated?
- when cellular damage (non-apoptotic cell death) leads to the release of damage associated molecular patterns (DAMPs) or
- the body detects pathogen associated molecular patterns (PAMPs)
What does the release of DAMPs and PAMPs cause?
causes the cells in the damaged tissue to secrete a range of signals designed to induce inflammation including molecules that alter the structure of nearby blood vessels and chemokines that promote the recruitment of immune cells to the site of injury
What is the aim of immune cell recruitment?
to clear the source of the initial inflammatory signal, and eventual resolution and repair of the inflamed tissue
How is the majority of inflammation categorised?
acute, with a rapid onset and resolution, and characterised primarily by the recruitment of innate cells into the tissue, in particular neutrophils
When can the state of chronic inflammation occur?
If the acute inflammatory response cannot remove the inflammatory stimuli however then other immune cells including adaptive immune cells are recruited
What is the difference between acute inflammation and chronic inflammation?
acute inflammation often resolves without any substantive damage to the surrounding tissue
– chronic inflammation can lead to repetitive rounds of inflammation, tissue damage and repair, resulting in scarring and loss of tissue function.
What is inflammation?
non-specific response to cellular injury
What is the role of inflammation?
to remove the cause and consequence of injury
universal process in health and disease
What are the 4 main signs of acute inflammation?
- redness (RUBOR)
- heat (CALOR)
- swelling (TUMOR)
- pain (DOLOR)
What are the causes of inflammation?
- Pathogens
- Allergens
- Auto-antigens
- Physical damage
- Extreme temperatures
- Non-apoptotic cell death
What cell types can be inflamed?
any cell types from epithelial and endothelial to specialised blood cells
Inflammation is a universal process
immunity and infection
haematology
cell biology
genetic
What is the pathway of inflammation?
change in local blood flow
structural changes in the microvasculature
recruitment/ accumulation of immune cells + proteins
What is the structure the skin?
epithelium interstitium (mast cells + macrophages) vascular endothelium (leukocytes + neutrophils)
What happens when theres a wound?
- inflammatory signals
- vasodilators released
- vascular changes
What are the inflammatory signals?
- non-apoptotic cell death
- detection of foreign material
What vasodilators are released?
- histamine
- nitric oxide
What vascular changes occur?
- increased permeability
- dilation
- reduced flow
- plasma leakage
What are the benefits of increased vascular permeability and leakage?
more antibodies
more protein
more barrier
more leukocyte migration
What is histamine?
sources: mast cells, basophils, platelets
actions: vasodilation, increased vascular permeability, endothelial activation
What are prostoglandins?
sources: mast cells, leukocytes
actions: vasodilation, pain, fever
What are cytokines? (TNF, IL-1)
sources: macrophages, endothelial cells and mast cells
actions: endothelial activation (adhesion molecules), fever, malaise, pain, anorexia, shock
What are chemokines?
sources: leukocytes, activated macrophages
actions: chemotaxis, leukocyte activation
What are complement? (C5a, C3a, C4a)
sources: plasma (produced in the liver)
actions: leukocyte chemotaxis and activation, vasodilation (mast cell stimulation), opsonisation