inflammation and repair Flashcards
4 major signs of inflammation
heat, redness, swelling, pain
name immunes cells in circulation
monocytes, leukocytes (neutrophils, basophils, eosinophils), platelets, lymphocytes
name 3 cells that recognize infection and produce inflammatory mediators
macrophages, dendritic cells, mast cells
what inflammatory mediators are released by macrophages, DCs, mast cells?
amines, cytokines (IL-1, IL-6, IL-12, IL-18)
what is different about capillaries in normal vs inflammation?
normal: most capillaries are empty
inflamation: vasodilation -> blood flows through most capillaries (hyperemia)
what is hyperemia?
increased blood flow
what is transudate? exudate?
transudate: Fluid that exits the capillaries under normal circumstances.
exudate: fluid containing metabolites and proteins
what changes in pressure happen during acute inflammation?
increase in hydrostatic pressure in all areas of microcirculation, and decrease in colloidal osmotic pressure
what is edema? (part of inflammation)
local swelling at the site of injury
what is histamine’s role?
increases vasodilation in arterioles and endothelial contraction in venules (leaky venules)
give an example of a delayed prolonged response?
sunburn
what is margination?
during inflammation when RBCs are clustered at the center and larger leukocytes become pressed against the venule wall
what protein is responsible for leukocytes slowing down? and stopping?
slow down = selectins
adhesion = integrins
what induces selectins?
cytokines and histamine
what is PECAM-1 (CD31)?
adhesion molecule found on the neutrophil and the endothelial cell wall that helps pull neutrophil through the gap between the endothelium wall
what kind of receptors on leukocytes sense chemokines
G-protein coupled receptors
what cells are recruited by chemokines?
TH1 and TH2
what cells are the first to arrive at site of inflammation
neutrophils
where do neutrophils come from? how long do they last?
bone marrow; die after a few days
what do NETs do?
Traps the microbe and stops the bacteria from travelling to other tissues
what are the precursors of macrophages?
monocytes
what are macrophage’s roles?
phagocytose bacteria, produce inflammatory mediators,
synthesize molecules for blood clotting, cell growth, tumor growth, collagen production, antibacterial defenses… ,
initiation of the immune response,
cleanup operations,
induction of general effects like fever, acute phase reaction, cachexia, loss of appetite
what are other names for macrophages?
microglial cells in CNS, interstitial dendritic cells, alveolar macrophages in lungs, kupffer cells in liver, osteoblasts in bones
what immune cells are involved in allergic and immune reactions
eosinophils and basophils
name 3 macrophages types and their role
classically activated macrophage: attack microbes
wound-healing macrophages: tissue repair
regulation macrophages: anti-inflammatory
steps of inflammatory reactions from day to day
day 1: edema
day 2: neutrophils
day 3: monocytes/macrophages
what do TLRs detect? what do they trigger?
detect pathogens, trigger inflammation
what do lectins detect?
fungal polysaccharides
describe the steps of phagocytosis
- recognition: PRRs recognize PAMPs (ex IgG, C3b), complement components
- engulfment: by phagosome
- killing and digestion: through lysosomal enzymes with free radicals
- extrusion
what are vasoactive mediator’s role?
Lead to vasodilation and increase the vascular permeability
name 2 vasoactive amines and their origin
histamines: released by degranulation of mast cells, basophils, platelets
serotonin: released by platelets
what are plasma proteases (type of vasoactive mediators) role?
increase permeability and edema
what are C reactive proteins and what do they do
involved in inflammatory processes and play an important role in various disease states
3 roles of complement?
lysis of bacteria,
chemotaxis,
opsonization
briefly describe the complement activation pathways
classical pathway: C1 binding to antibodies -> triggers vasodilation, edema, MAC
lectin pathway: triggered by microbe; use of mannose-binding lectin
alternative pathway: triggered by microbe; generates C3b
what is the outcome of all the complement pathways?
C3 is cleaved, C3a and C5a are released, C3b opsonin and C5a chemoattractant are also released, C5b-C9 form the MAC