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15 Cards in this Set
- Front
- Back
Five Major Components of the extracellular matrix
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1. Collagen
2. Basement Membrane 3. Structural Glycoproteins 4. Elastic fibers 5. Proteoglycans |
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Describe four phases of normal cell growth factor.
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M (mitosis) Phase - Interval between onset of the mitotic prophase and the end of telophase.
G1 (GAP) Phase - Presynthetic; following mitosis the cell is devoted to its specialized activity. S (Synthesis) Phase - Doubling of DNA takes place G2 Phase - Postmitotic; following DNA synthesis, before next M phase (mitosis) |
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Three groups of cells of the body based on their regenerative capacity, give examples of each
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LABILE - continuously dividing (epeidermis and GI, resp., urinary, genital gract mucosa, bone marrow, lymphoid tissue (stem cells))
STABLE - Lowe level of replication usually, but can undergo raid division in response to tissue injury; (endocrine, endothelium) PERMANENT - Nondividing, cannot undergo mitotic division postnatally; (neurons, cardiac myocytes, lens cells) |
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Define cell matrix interactions
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The physical contact between cells and their surrounding extracellular matrix.
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Why cell-matrix interactions are important
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The structural and functional inegrity of normal mature tissues depends on a close relationship between cells and their surrounding CT matrix. Cell migration and differentiation during would healing also depends on this integrity.
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Cytokine Function
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Cytokines are soluble proteins that bind to specific cell surface receptors, and stimulate mitogenic growth factors in order to modulate cell behavior
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Types of Cytokines
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Macrophage -derived Growth Factor
Platelet Derived Growth Factor, Epidermal Growth Factor Fibroblast Growth Factor Transforming Growth Factor - B |
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Three (3) Mechanisms of wound healing that operates simulatneously after the inflammatory phase.
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CONTRACTION - inward migration of surrounding mesenchymal cells causes an initial reduction in size of wound; myofibroblasts then migrate within 2-3 days after injury actively contracting the size of the lesion.
REPAIR - wound is eventually replaced by a scar formed from granulation tissue as a result of a process of angiogenesis ( Pronounced vascular proliferation), cell proliferation, and collagen synthesis. REGENERATION - Missing cells are replaced by new ones. |
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Differentiate between healing of wounds by primary and secondary intention.
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PRIMARY - healing of clean incision.
Secondary - Occurs with more extensive loss of tissue or failure to approximate edges. |
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Four local factors which influence wound healing
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Type, size, location
Vascular supply Infection Movement |
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Four systemic factors that influence wound healing.
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Circulatory Status
Infection -septic pt./embolus Metabolic status Nutritional Status |
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Two factor which would lead to deficient scar formation
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A: Wound dehiscence - most common after abdominal surgery due to increased mechanical stress from abnormal movements such as vomiting, coughing, etc. or from systemic factors that predispose such as poor metabolic status.
B: Ulceration - due to inadequate intrinsic blood supply to injured area. |
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Keloids and Contractures
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KELOID - Excessive deposition of extracellular matrix resulting in hypertrophic scar.
CONTRACTURE - Exaggerated healing causing deformity of wound and surrounding tissue. |
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Types of Collagens
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Type I - Bone, skin, tendon
Type II - Cartilage Type III - Embryo, blood vessels, uterus, GI Type IV - Exclusively the Basement Membrane |
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Epithelia
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All epithelia (epidural, endocrine, genitourinary, respiratory, GI) are separated from the stroma by continuous basement membranes.
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