Presentation on theme: "Chapter 4 Cell Proliferation, Tissue Regeneration and Repair"— Presentation transcript:
1Chapter 4 Cell Proliferation, Tissue Regeneration and Repair
2Pre Lecture Quiz True/False 1. Stem cells are undifferentiated cells that have the capacity to generate multiple cell types.2. DNA synthesis takes place during the G0 phase of the cell cycle.3. The inflammatory phase of wound healing prepares the wound environment for the healing process.4. The formation of granulation tissue involves the creation of new capillaries.5. A large surface wound is likely to heal by the process of primary intention.
3Fill-in-the-Blank growth keloids matrix Scar Stable 1. _____________ tissues contain cells that normally stop dividing when growth ceases. 2. The extracellular _____________ is secreted locally and assembles into a network of spaces surrounding tissue cells during the process of tissue regeneration. 3. When regeneration cannot occur, healing by replacement with a connective tissue occurs, a process that terminates in ______________ formation. 4. The term _____________ factor is generally applied to small hormonelike proteins that increase cell size and cell division. 5. An abnormality in healing by scar tissue repair is the formation of _____________, which are benign tumorlike masses caused by excess production of scar tissue.growthkeloidsmatrixScarStable
4Cell Proliferation and Tissue Regeneration Parenchymal tissueStromal tissueThe working partThe binding part
5Cell Proliferation Versus Differentiation Cell proliferation-process of increasing cell numbers by mitotic divisionCell Differentiation-process whereby a cell becomes more specialized in terms of structure and function
7Proliferative Capacity of Tissues Varies with tissue and cell type3 divisions of body tissues:Continuously doublingStablePermanent tissues
8Stem Cells Incompletely differentiated throughout life 3 Properties: Self-renewalAsymmetric replicationDifferential potential (potency)
9Influence of Growth Factors Small hormonelike proteins that increase cell size and cell divisionPDGF, FGF, TGF, and EGF
10Extracellular Matrix and Cell-Matrix Interactions ECM is secreted locally and assembles a network of spaces surrounding tissue cellsComponents of ECM:Fibrous structural proteinsWater-hydrated gelsAdhesive glycoproteins
13Phases of Repair Angiogenesis and ingrowth of granulation tissue Emigration of fibroblasts and deposition of extracellur matrixMaturation and reorganization of the fibrous tissue (remodeling)Usually begins within 24 hours of injury; evidenced by the migration of fibroblasts and the induction of fibroblast and epithelial cell proliferation
20Factors that Affect Wound Healing Nutritional StatusBlood Flow and Oxygen DeliveryAge
21Nutritional Status Local and systemic factors influence wound healing Vitamin C and A play an essential role in the healing processVitamin C is needed for collagen synthesisVitamin A functions in stimulating and supporting epitheilial
22Blood Flow and Oxygen Delivery For healing to occur, wounds must have adequate blood flow to supply the necessary nutriients and to remove waste, local toxins, bacteria and other debris.
23Wound Healing in the Elderly Age-related changes:A decrease in dermal thicknessA decline in collagen contentLoss of elasticityElderly are more vulnerable to chronic wounds, such as pressure, diabetic, and ischemic ulcers as compared to younger persons