1. Chapter 4 Cell Proliferation, Tissue Regeneration and Repair

2. Pre 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.

3. Fill-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.
growth
keloids
matrix
Scar
Stable

4. Cell Proliferation and Tissue Regeneration
Parenchymal tissue
Stromal tissue
The working part
The binding part

5. Cell Proliferation Versus Differentiation
Cell proliferation-process of increasing cell numbers by mitotic division
Cell Differentiation-process whereby a cell becomes more specialized in terms of structure and function

6. The Cell Cycle
4 distinct phases

7. Proliferative Capacity of Tissues
Varies with tissue and cell type
3 divisions of body tissues:
Continuously doubling
Stable
Permanent tissues

8. Stem Cells Incompletely differentiated throughout life 3 Properties:
Self-renewal
Asymmetric replication
Differential potential (potency)

9. Influence of Growth Factors
Small hormonelike proteins that increase cell size and cell division
PDGF, FGF, TGF, and EGF

10. Extracellular Matrix and Cell-Matrix Interactions
ECM is secreted locally and assembles a network of spaces surrounding tissue cells
Components of ECM:
Fibrous structural proteins
Water-hydrated gels
Adhesive glycoproteins

11. Components of the ECM

12. Healing by Connective Tissue Repair

13. Phases of Repair Angiogenesis and ingrowth of granulation tissue
Emigration of fibroblasts and deposition of extracellur matrix
Maturation 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

14. Angiogenesis and Ingrowth of Granulation Tissue

15. Maturation and Remodeling of the Fibrous Tissue

16. Cutaneous Wound Healing
The transition from granulation to scar tissue shifts in the modification and remodeling of the ECM

17. Healing by Primary and Secondary Intention
Primary intention –sutured surgical incision
Secondary intention- larger wounds which have a greater loss of tissue and contamination

18. Phases of Healing Inflammatory Phase Proliferative Phase
Maturational or Remodeling

19. Keloids

20. Factors that Affect Wound Healing
Nutritional Status
Blood Flow and Oxygen Delivery
Age

21. Nutritional Status Local and systemic factors influence wound healing
Vitamin C and A play an essential role in the healing process
Vitamin C is needed for collagen synthesis
Vitamin A functions in stimulating and supporting epitheilial

22. Blood 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.

23. Wound Healing in the Elderly
Age-related changes:
A decrease in dermal thickness
A decline in collagen content
Loss of elasticity
Elderly are more vulnerable to chronic wounds, such as pressure, diabetic, and ischemic ulcers as compared to younger persons