Hunter: Inflammation Flashcards
(blank) is a component of the innate immune response to pathogenic microorganisms.
inflammation
In addition to the anti-microbial response, inflammation plays a key role in dealing with the consequences of cell and tissue (blank) caused by microbes and other physical and chemical insults
injury
What would happen without inflammation?
pathogenic microbes would overwhelm us
injured tissues would never heal
T/F: Inflammation is sometimes inappropriately triggered or poorly controlled, and is sometimes the CAUSE of tissue injury in many disorders.
True
Give an example of inflammation having a protective response. Give an example of inflammation having a harmful response.
protective: Streptococcus pyogenes (impetigo)
harmful: rheumatoid arthritis
Inflammation was recognized long ago. What were the four cardinal signs of inflammation noted? What is a 5th?
rubor (redness)
tumor (swelling)
calor (heat)
dolor (pain)
T/F: Inflammation is not a disease, but a nonspecific response that can be both protective and harmful to the host.
True
Pluripotent hematopoietic stem cells can give rise to two lines of cells. Which lineage produces dendritic cells, granulocytes (neutrophils, eosinophils, basophils), platelets, mast cells, and erythrocytes?
myeloid lineage
What two cells are the primary sensors of acute inflammation?
mast cells
macrophages
What’s this: source of mediators, such as histamine
mast cell
What’s this: cell involved in elimination of microbes and dead tissue. A source of mediators. Has a role in immune response. Also, Dr. H’s favorite cell.
macrophage
Describe the inflammatory process in a simple way. What four components are involved?
Inducers –> sensors –> mediators –> target tissues
INDUCERS of inflammation can be exogenous signals or endogenous signals that report on tissue stress, injury, or malfunction. What do these respond to?
danger signals!!
SENSOR CELLS, such as tissue-resident macrophages and mast cells, detect inducers with specific mediators and respond by producing what?
inflammatory mediators
Inflammatory mediators act on TARGET TISSUES to alter their functional states, promote elimination of inducers, adaptation to the noxious state, and restore (blank)
tissue homeostasis
Although leukocytes are the primary effector cells of inflammation, what other cells play a critical role?
endothelial cells
Give an example of a mediator that modifies endothelium adjacent to various mediators and attracts leukocytes to allow them to pass into the tissues
TNF-alpha
The endothelium also becomes permeable to (blank), thus allowing molecules like antibodies to gain access to the tissues.
plasma
List some stimuli for inflammation.
infections and microbial toxins
tissue necrosis for any cause (ex: trauma, physical/chemical injury, hypoxia)
hypersensitivity reactions (normally protective immune system damages cells and tissues)
List a few examples of hypersensitivity reactions or immunopathology
autoimmune diseases
allergies
Inflammation can be triggered by (blank) from pathogens. Phagocytic cells have (blank) on their surface and bind to highly conserved molecular motifs on pathogens called (blank).
danger signals; pattern recognition receptors; pathogen-associated molecular patterns
What does recognition of PAMPs trigger?
production of inflammatory mediators –> INFLAMMATION –>
destruction of the pathogen
These are expressed on phagocytic cells and recognize highly conserved PAMPs found on viruses, bacteria, etc. List a couple PRRs.
Toll-like receptors (can be extracellular or intracellular) Other PRRs (ex: Dectin-1)
In addition to pathogens, what else can induce inflammation?
tissue injury (necrosis)
Does necrosis trigger inflammation? Does apoptosis trigger inflammation?
YES; no
Cell injury or necrotic death causes the release of damage-associated molecular patterns (DAMPs). What are these also referred to as?
alarmins
Phagocytic cells recognize DAMPs and activate intracellular signaling pathway and the production of inflammatory mediators. What does this lead to?
inflammation and tissue regeneration or repair
Inflammation can cause (blank) to normal tissues. When it is inappropriately directed against self tissues it can becomes the CAUSE of injury/disease. List some common chronic diseases in which this is the case.
collateral damage; rheumatoid arthritis, atherosclerosis
Is inflammation critical to tissue repair? When does tissue repair begin? When does it end?
Yes; repair begins during inflammation, ends after the injurious agent has been neutralized
Through what two processes is injured tissue replaced?
regeneration of native parenchymal cells
filling of defect with fibrous tissue
OR…both!
T/F: Inflammation can be acute OR chronic, and this depends on the nature of the stimulus and how effective the initial reaction is in eliminating the stimulus and damaged tissues.
True
What happens after an offending agent is eliminated to prevent excessive damage to the host?
mediators rapidly broken down
neutrophils are short-lived
anti-inflammatory mechanisms
Is a sunburn an acute or chronic inflammation? What about psoriasis?
acute; chronic
Rapid host response that delivers leukocytes and plasma proteins to site of infection
acute inflammation
During acute inflammation, what happens to blood supply and flow? What happens to vascular permeability? What does this lead to? What happens to leukocytes?
VASODILATION increases blood supply (hyperemia), but actually decreases flow rate (stasis). Increased vascular permeability, which leads to edema. Recruitment, adhesion, transmigration of leukocytes across blood vessels.
What is it called when leukocytes flock to the site of infection or tissue injury? What is the process called in which pathogens are engulfed, destroyed, and eliminated.
chemotaxis; phagocytosis
What is the first manifestation of inflammation? What is this often preceded by? What is it caused by? What is it the result of?
vasodilation; preceded by vasoconstriction; caused by specific mediators released from tissue phagocytic cells; it is the result of relaxation in smooth muscle surrounding blood vessels
What mediators cause vasodilation? Dilation results in greater blood volume but slower flow. What is this called? What does dilation cause tissue to show?
histamine and NO; stasis; vascular congestion