Inflammation-Hunter Flashcards
What is the purpose of inflammation?
it is an innate immune response to deal w/ microbes & necrosis (from any cause). Need to get rid of pathogens & need to heal.
T/F Inflammation can be both good & bad–>it is a double edged sword.
TRUE
What are some examples where inflammation is good & an example where inflammation is bad?
Good inflammation: impetigo in response to streptococcus pyogenes; function of vaccines requires inflammation w/ exposure
Bad inflammation: rheumatoid arthritis
What are the features of inflammation that were recognized long ago?
Redness (Rubor) Swelling (Tumor) Heat (Calor) Pain (Dolor) Loss of Function (functio laesa)
T/F Inflammation is in itself a disease.
FALSE. It is a nonspecific response that can be helpful or harmful.
Where is the “mama” of the immune system located? How does this relate to inflammation?
Bone marrow: “mama” of the immune system
produces a bunch of the cells involved in inflammation
Pluripotent hematopoietic stem cells give rise to 2 lineages.
Lymphoid & Myeloid.
Myeloid is our focus. These are released into the blood.
Most important cell of this lineage: neutrophil
Other important cell: monocyte–>differentiates into macrophages!
Mast cells also found here.
What is another name for neutrophils?
polymorphonuclear leukocyte
Where are mast cells usu found?
usu found in the tissues. Often found in CT & lining blood vessels. Less often found in the blood.
What are the primary sensors of acute inflammation? What do these cells do?
mast cells & macrophages (main guy)
these cells recognize tissue damage (from a variety of causes) & can recognize specific microbes (b/c they have receptors on their surface).
They then release mediators & orchestrate the inflammation response.
When the mast cells & macrophages (main guy) orchestrate the acute inflammatory immune response…which players do they get in the game?
hematopoietic cell types neutrophils! plasma proteins (complement) endothelial cells lining blood vessels (to release stuff)
Describe the order of the inflammatory process in general terms.
Inducer damages tissue.
Sensors recognize the damage & release mediators.
Mediators go to the target tissue & eliminate inducers & try to achieve homeostasis.
What are inducers?
exogenous or endogenous signals that report tissue damage, injury, or malfunction
could be trauma, burn, pathogens, toxins, ATP, urate crystals etc.
**they start the inflammatory process b/c they cause the problem
What are sensors?
tissue resident macrophages & mast cells that detect inducers w/ their specific receptors & release mediators for the inflammatory response.
In addition to macrophages & mast cells, what is another sensor?
dendritic cell
What are some examples of mediators & their classes?
cytokines: TNF, IL-1, IL-6
chemokines: CCL2, CXCL8
Vasoactive amines: histamine, bradykinin
Eicosanoids: includes prostaglandins
Direct Activation of a Sensor produces? Indirect activation of a sensor produces?
Direct Activation: good inflammation, get rid of a pathogen
Indirect Activation: bad inflammation, collateral damage of tissue
So, a macrophage senses a pathogen. What does it release to communicate to the endothelial cells lining blood vessels? Why is it important to communicate to these endothelial cells?
Among other things, it releases TNF alpha.
TNF alpha goes to the endothelial cells & says “hey, join the inflammation team!”
Endothelium attracts leukocytes, including neutrophils, & lets them pass into injured tissue.
It also becomes permeable to plasma & lets antibodies & fluid into the damaged tissue.
We have said that the main causes of inflammation (as sensed by macrophages & mast cells) are pathogens & tissue necrosis. What are some specific infections that can prompt inflammation?
bacterial infection viral infection fungal infection parasitic attack microbial toxins
We have said that the main causes of inflammation (as sensed by macrophages & mast cells) are pathogens & tissue necrosis. What are some specific causes of tissue necrosis that can cause inflammation?
Ischemia (MI)
Physical or Chemical Trauma (thermal injury, irradiation, environment chemicals, foreign bodies)
Hypoxia
An MI produces coagulative ischemic necrosis. What type of inflammation does it produce?
sterile inflammation
What are hypersensitivity reactions? What are they also called? What are some examples?
Also called immunopathology
normally protective immune system inflammation rxn damages cells & tissues
Ex: autoimmune diseases & allergies
When inducers are pathogenic microorganisms…what signal do they have & how is they recognized such that they trigger inflammation?
Inducer: pathogen–>has danger signal/PAMP
Sensors/Phagocytic Cells (macrophages): have PRR that bind PAMP.
Intracellular signaling pathway & activation of macrophages.
They release mediators for inflammation & get goin’ on their phagocytosis.
Then you get rid of the pathogen & you get tissue regeneration & repair.
What does PAMP stand for?
What does PRR stand for?
PAMP: pathogen-associated molecular patterns
PRR: pattern recognition receptors
What are some specific examples of PRRs found on sensor cell surfaces?
TLR: toll like receptors *found on plasma membrane & intracellularly Ex: TLR-5--sees flagellum. Other: Dectin-1: recognizes beta glucans. Fights fungi. CRD/mannose receptor Complement Receptor Scavenger Receptors: SR-A, MARCO Lipid Receptor: CD36