4 Inflammation and repair--Part I Flashcards
What is inflammation?
A localized response to infection and injury intended to eliminate the initial cause of injury and initiate the process of repair
What are the four external manifestations of inflammation?
heat (calor), redness (rubor), swelling (tumor), and pain (dolor)
What are the 5 Rs of the inflammatory response?
1) Recognition of the injurious agent
2) Recruitment of leukocytes
3) Removal of the agent
4) Regulation of the response
5) Resolution/repair
What are the three major classes of leukocytes in the inflammatory response?
monocytes, neutrophils, and lymphocytes
What is the role of T and B lymphocytes in inflammatory responses?
Mediate antigen-specific immune and inflammatory responses
What is the role of neutrophils and monocytes in inflammatory responses?
phagocytic cells responsible for removal of dead cells and debris
Infiltration of tissues with what cell type is the hallmark of acute inflammation?
neutrophils
Infiltration of tissues with what cell types is the hallmark of chronic inflammation?
lymphocytes and monocytes
T or F: acute inflammation is mediated by the adaptive immune system.
F: it is mediated by the innate immune system
What are the functions of acute inflammation?
phagocytose bacteria, remove necrotic tissue, and initiate process of tissue repair
Briefly summarize the sequence of events that constitute acute inflammation.
1) increased blood flow
2) increased vascular permeability
3) extravasation and deposition of fluid and plasma proteins
4) emigration of neutrophils from the microcirculation to the site of injury
What chemical mediator of inflammation increases vascular permeability by inducing retraction of endothelial cells?
Histamine
what are the two types of extravascular fluid loss?
transudate and exudate
What changes in Starling forces contribute to an increase in transudate?
increased hydrostatic pressure without increase in vascular permeability, and decreased vascular colloid pressure due to low protein count
What conditions contribute to an increase in exudate?
Increased vascular permeability due to inflammation
What does exudate contain?
high protein content, inflammatory cells, and cellular debris
T or F: both transudate and exudate have a high protein content.
F; transudate has a very low protein content, while exudate has a much higher protein content
Edema due to increased pressure, such as edema in the extremities caused by congestive heart failure, is an example of what type of extravascular fluid?
transudate
In which areas of the human body is localized edema particularly dangerous?
larynx (asphyxiation), brain/meninges (herniation), and lungs (poor gas exchange)
what are the different types of exudates?
serous (fluid), fibrinous (fibrin and other plasma proteins), sanguineous (bloody), and purulent (contains neutrophils)
A skin blister with an accumulation of clear fluid contains what type of exudate?
Serous exudate
Pericarditis, which results in protein deposition on the epicardial surface, is an example of what type of exudate?
Fibrinous exudate
A bacterial abcess contains which type of exudate?
purulent exudate
what are the cellular components of pus?
necrotic tissue and live and dead neutrophils
What causes tissue damage during acute inflammation?
release of proteolytic enzymes and ROIs during frustrated phagocytosis
What are the two different types of adhesion necessary for extravasation of leukocytes into tissues, and which proteins are responsible for mediating both types of adhesion?
loose rolling interaction mediated by selectins and firm adhesion mediated by integrins
what is the role of cytokines in leukocyte migration into tissues?
local secretion of cytokines induces endothelial adhesion molecules
what is the role of chemokines in leukocyte migration into tissues?
chemokine deposition on endothelial surfaces triggers increased integrin affinity; also important for chemotaxis
what are the three steps in leukocyte migration into tissues?
rolling, firm adhesion, and transmigration
Locomotion oriented along a chemical gradient is known as ______.
chemotaxis
T or F: Chemoattractants for leukocytes include both exogenous and endogenous substances.
T; exogenous sources are bacterial products and endogenous sources are complement, cytokines, chemokines, and lipoxygenase products
what type of leukocytes predominate in the first 6-24 hours of acute inflammation? in the first 24-48 hours?
neutrophils in the first 6-24, monocytes in the first 24-48
T or F: in acute viral infections, neutrophils are the first cells to arrive
F; lymphocytes are the first to arrive in acute viral infections
What are the three steps of phagocytosis of ingested particles?
1) recognition and attachment of particle to leukocyte
2) engulfment of particle and subsequent formation of a phagocytic vacoule
3) degradation of ingested material
What are the three possible outcomes of acute inflammation?
resolution of inflammation, progression into chronic inflammation, and fibrosis of affected tissue
