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39 Cards in this Set
- Front
- Back
Angiogenesis
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Formation of new BV
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Cicatrix
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Scar
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Fibrosis
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Formation of fibrous tissue in repair or replacement of cellular elements
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Keloid
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Sharply elevated, irregular scar due to excessive collagen formation during tissue repair
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3 parts of tissue repair
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1) removal of exudate
2) Removal of cellular and tissue debris 3) replacement of lost cells and tissue |
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3 types of cells w.r.t regeneration
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1) Labile - Continue to proliferate throughout life (always in mitosis)
2) Stable - Low replication level but can divide in response to stimuli (always in G0 but can go to G1) 3) Permanent - Cannot divide in postnatal life (CNS neurone) |
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4 places physiological regeneration takes place
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1) Epidermis
2) Blood 3) Uterine mucosa 4) Glandular epithelium |
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What type of tissue regenerates best
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Supporting tissue (Connective tissue, epithelium)
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Atypical regeneration
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When some framework of a tissue was destroyed and regeneration does not include that framework
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Where can organ regeneration occur in mammals
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Liver, lung, kidney, spleen
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What are the two mechanisms involved in regeneration and repair
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1) Control of cell proliferation
2) Collagenization and acquisition of wound strength |
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What types of cells are best-used for growth
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Recruitment of stable cells from G0
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What 3 ways can stable cells be activated
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1) Growth or stimulatory factors (ie insulin, somatotropin, estrogen)
2) Loss of a growth inhibitor (Negative feedback) ie 3) Cell-cell or cell-matrix interactions (Dependent on density) |
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Cell-matrix interactions
-how they work |
Cells have receptors that recognize the extracellular matrix and interact with certain proteins that control cell proliferation
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Name the main type of cell-matrix receptors and 3 types
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Integrins
1) Fibronectin 2) Platelet surface 3) Leukocyte adhesion |
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What are 5 structures in the extracellular matrix (ECM)
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1) Collagens
2) Glycosaminoglycans 3) Proteoglycans 4) Glycoproteins 5) Fibronectins |
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What is the most important structure in the ECM
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Fibronectins
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3 locations of fibronectins
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1) Cell surfaces
2) Basement Membranes 3) Pericellular Matrices |
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3 cells that produce fibronectins
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1) Fibroblasts
2) Endothelial 3) Monocytes |
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4 Functions of fibronectins
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1) Migration of epithelium
2) Chemotaxis for monocytes and fibroblasts 3) stimulate endothelial migration and organization 4) Release bFGF from monocytes |
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When does collagenation occur and why
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When the injury caused damaged to parenchymal cells and stromal framework, and regeneration will not heal injury
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Steps of collagenization
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1) Non-regenerated parenchymal cells replaced by fibroblasts and endothelial cells
2) Granulation tissue is established |
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Granulation tissue
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granular tissue made of capillaries fibroblasts and INF cells that acts as scaffold for final scar to form
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3 Steps in repair process
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1) Angiogenesis
2) Fibrosis 3) Maturation and organization of scar |
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1) Angiogenesis in repair
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New vessels bud off of old ones, and are leaky causing edema
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What are the two chemical mediators of Angiogenesis in tissue repair
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1) VEGF - Vascular endothelial growth factor
2) bFGF - Fibroblast growth factor |
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Fibrosis in tissue repair
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Occurs by proliferation of fibroblasts and deposition of ECM by these cells
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Maturation/organization of scar in tissue repair
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Collagen and other ECM degraded by metalloproteinases
Cleave 4 types of collagen and fibronectin produced by INF cells and epi cells |
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Most common protein in animal world
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collagen
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5 types of collagen and which are fibrillary/amorphous
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I, II, III fibrillary
IV, and V amorphous |
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What cells digest collagens
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Collagenases, metalloproteinases
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What produces elastic fibres and what are their two components
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Fibroblasts
elastin and elastic microfibril |
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What collagen types are in
Adult skin Granulation tissue Cicatrization |
I
III III replaced by I |
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5 Steps of skin wound repait
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1) crust formation
-stops bleeding -bars infection 2) Removal of dead tissue, debris, and exudate -usually falls off or is phagocytosed 3) Replacement of lost cells and tissues -cell migration and division -new tissue with rapidly proliferating cells (granulation tissue) is created 4) Epithelium -Requires something to migrate on (Gran tissue) -in larger skin wounds, passes between crust and gran tissue -scab drops off 5) Cicatrization -conversion of gran tissue to scar (closure of small vessels) |
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3 types of proliferating/migrating cells in skin wounds
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1) Fibroblasts
2)Endothelium 3) Epithelium |
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Keloid
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connective tissue proliferation that goes above and beyond what is needed.
red, raised lesion with a shiny surface |
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Primary Repair/Primary Union/First Intention
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- a superficial wound that goes into the epidermis but not the dermis (no blood)/ or deeper into the dermis causing some blood which cement the wound/ deep enough that retraction occurs and sutures may be needed
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Secondary Repair (Second Intention
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Considerable loss of tissue
requires creation of gran tissue |
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3 stages of wound closure
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1) Latent period ( Size does not change, 1-2 days)
2) Contraction period (Shrinkage of gran tissue, edges are pulled together) 3) Epidermization (Epidermis recreated) |