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13 Cards in this Set
- Front
- Back
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... - An outcome of inflammation that is characterized by regeneration and/or scarring
...: -Replacement of injured cells by healthy cells of same type -full reconstitution of architecture and function -growth of amputated limb in amphibian ... (AKA...): -Replacement of injured cells by connective tissue -This process ultimately leads to scar formation -Occurs in tissue not capable of healing by regeneration |
Healing
Regeneration Scarring fibrosis |
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Healing/Repair:
Healing of an injured tissue may occur solely by either ... or...; in most cases both processes are involved, with one process usually predominating over the other Repair -Some use the term as a synonym for "healing” -Others use the term to refer exclusively to scarring, e.g. "repair by scar formation", "repair by fibrosis " |
regeneration
scarring |
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Cell cycle represents phases that a cell experiences while it prepares for ....
... = cell is actively synthesizing DNA. ... = presynthetic phase ... = postsynthetic (premitotic) phase ... = intermitotic (resting) phase. Cell is "out" of the cell cycle |
mitosis
S G1 G2 G0 |
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Tissue proliferative activity:
... Tissues: -short G0 -continually dividing throughout life -these tissues contain stem cells which have an unlimited capacity to proliferate -surface epithelium (skin, oral cavity, vagina, cervix) -columnar epithelium of GI tract and uterus -lining mucosa of excretory ducts (salivary glands, pancreas, biliary tract) -transitional epithelium of urinary tract -bone marrow |
Labile
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Tissue proliferative activity:
... (...) Tissues: -normally have a low level of replication -Prolonged G0 (sometimes for years) -They re-enter cell cycle only under certain conditions, such as healing Include: - parenchymal cells of liver, pancreas, kidney -fibroblasts, chondrocytes, osteocytes, and smooth muscle -vascular endothelial cells -leukocytes |
Stable
Quiescent |
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Tissue proliferative activity:
... (...) Tissues: -Have left cell cycle forever -Cannot undergo mitosis postnatally -Cardiac muscle -Skeletal muscle* -Neurons* |
Permanent
Non-dividing |
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What are these?
-Polypeptides -May promote cell proliferation by recruiting G0 cells into the cell cycle (mitogenic) -May inhibit cell proliferation by blocking cells from entering the cell cycle. -They may influence other cell functions besides growth, e.g. cell differentiation, cell migration through tissues (chemotactic), angiogenesis |
Growth factors
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Extracellular matrix:
Two major components: ... : -Collagen -Elastin -Fibronectin (adhesive glycoprotein) -Others ... : -Laminin (adhesive glycoprotein) -Collagen -Others |
Interstitial matrix
Basement membrane |
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Sequence of cellular / biochemical events involved in repair by fibrosis:
24 hours after tissue injury, ... and vascular endothelial cells proliferate This leads to the formation (by 3 - 5 days after injury) of ... tissue, so-called because of its pink, soft, granular appearance |
fibroblasts
granulation |
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Important features of granulation tissue:
***Proliferation of newly formed small blood vessels (...)*** -The new vessels originate, in part, from "..." of pre-existing blood vessels that are within the area of repair -The new vessels are immature and have leaky interendothelial junctions, allowing an exudate to form --> therefore granulation tissue is ... -Angiogenesis involves several growth factors, particularly ... and also ... --> these factors stimulate endothelial mitosis and migration to the new blood vessels |
angiogenesis
budding edematous VEGF FGF |
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Sequence of cellular / biochemical events involved in repair by fibrosis :
Weeks to months after onset of injury, granulation tissue is transformed into a mature scar -Amount of collagen, as well as other ECM proteins, ... -Number of fibroblasts, as well as vascularity, ... -Fully mature scar is practically..., has very few cells, and has much dense collagen --> it has been remodeled |
increases
decreases avascular |
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Embryonic Stem cells:
..., can give rise to all tissues of the body Can be isolated from ... (structures formed at about the 32 cell stage of development) Can be maintained in culture as undifferentiated cells or may be induced to differentiate Have made possible the production of knockout mice -a specific gene is inactivated or ... from cultured embryonic stem cells -these cells are injected into blastocysts which are implanted into uterus of surrogate |
Pluripotent
blastocysts deleted |
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What are these?
Have a more restricted differentiation capacity Generally Lineage Specific -however stem cells with broad differentiation potential have been found in adult bone marrow Located in “niches” -isthmus of gastric glands -base of the crypts of the colon -bulge area of hair follicle -limbus of cornea -canals of Hering in liver |
Adult stem cells
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