Inflammation 2 Flashcards
what does a successful inflammatory response do? an unsuccessful one?
- a successful inflammatory response to perturbation (injury, infection) restores homeostasis
- a pathological inflammatory response results in tissue damage and/or tissue remodeling
tissue remodeling
- development of new specialized cell types
- scarring or alteration of tissue function due to poor inflammatory response
tissue homeostasis
- regulation of normal tissue state
- tissue undergoes cell death & repair w/o causing problems when old or damaged
what is acute inflammatory response thought to be associated with?
- bacterial infections
- can also be due to stress or trauma; but typically if see acute response, assume bacterial
feed forward mean?
- is the idea that we can activate responses and products of the response (IL-1b or TNFa inflamm cytokines) can induce other cells to make more of it
feedback mean?
- production of a molecule leads to feedback inhibition of the initial trigger
feedback and feed forward processes?
- can have both going on at same time in certain pathways
- can be targets for therapeutic interventions in inflammation
5 clinical signs of acute inflammation?
1) Rubor (redness)
2) Calor (heat)
3) Tumor (swelling)
4) Dolor (pain)
5) laese functio (loss of function)
- most due to blood vessel responses*
Rubor
- redness in the skin
- increased blood flow= increased color
- smooth muscle in arterioles is relaxing causing increased diameter so blood can rush to area of inflammation
calor
- heat
- increased local blood flow= increased local temperature
- due to dilation, blood form our core (warmer blood) is moving to areas of inflammation faster so feel warmth
Arteriole vs venule? clinical features of inflammation involving which one?
- arteriole is higher pressure vessel ( involved in transudate)
- venule is thinner walled & no smooth muscle layer (involved in exudate)
clinical features in inflammation are due to arteriole changes
tumor
- swelling (edema)
- increased blood flow, causes changes in vascular permeability
- fluid can leak from blood vessels into extracellular matrix -causes the loose connective tissue to expand= edema
Two ways vascular circulation can contribute to extracellular fluid?
1) transudate
2) exudate
transudates
- swelling/edema
- due to altered balance between hydrostatic & osmotic pressure that pushes water and ions out of arteriole and into loose connective tissue
- (increased hydrostatic or decreased osmotic)
lymphatics & transudates
-lymphatics help remove some of the excess fluid transudates push into the connective tissue to release swelling during an inflammatory response
exudate
- swelling/edema
- due to induced changes in vessel permeability
- loose barrier function of endothelium (due to inflam toxic factors etc.)
- lead to direct leakage of H20 and serum, proteins, cells etc,
Exudation due to increased vascular permeability is due to what?
- can be from different inflammatory-induced effects
1) chemical mediators
2) chemical, toxin, or physical damage
3) leukocyte-mediated
4) endothelial transcytosis (loose epithelial barrier)
chemical mediators of exudation?
- Histamine
- common source= Mast cells
- can bind receptors at sites of inflammation & cause smooth muscle relation & vessel dilation
- results in swelling (tumor), and rash sometimes
steps for histamine release?
- mast cell is common source
- if have allergic response, IgE binds receptors, causes degranulation of mast cells, histamine released
- results in swelling (tumor), and rash sometimes
dolor
- pain
- can be caused by number of things including Arachidonic Acid (AA) metabolites
recruited leukocytes functions
1) production of cytokines to drive tissue responses
2) filling infectious microbes,
3) removal of cell debris
blood flow and inflammation
- classic sign of inflammation= recuritment of cells from blood
- heart pumps lymphocytes & neutrophils through blood, allows first responders to get to inflammation site ASAP
- poor profusin can impair inflamm response
neutrophils
- first responder
- rapidly recruited
- short lived (12-18hr)
- can enter, handle infection, eat up bacteria but arent actually clean up crew for the left over dead bacteria
macrophages
- later part of inflamm response -clean up crew of old dead bacteria left behind by neutrophils
- longer lived, can differentiate into specialized roles in clean up, wound repair & remodeling
What is pus?
-when have an accumulation of phagocytic cells that are killing bacteria, then leaving it and not enough macrophages to clean up bacterial remains