Term
| 5 components of the extracellular matrix |
|
Definition
*collagen
*basement membrane
*structural glycoproteins
*elastic fibers
*proteoglycans |
|
|
Term
| 4 Phases of normal cell growth cycle |
|
Definition
*M phase
*G1 phase
*S phase
*G2 phase |
|
|
Term
| 4 Phases of normal cell growth cycle |
|
Definition
*M phase
*G1 phase
*S phase
*G2 phase |
|
|
Term
|
Definition
| interval between onset of the mitotic prophase and the end of telophase |
|
|
Term
|
Definition
| presyntheic; following mitosis the cell is devoted to its specialized activity |
|
|
Term
|
Definition
| doubling of DNA takes place |
|
|
Term
|
Definition
| postmitotic; following DNA synthesis, before next M phase (mitosis) |
|
|
Term
| Describe three groups of cells of the body based on their regenerative capacity, and give examples of each. |
|
Definition
*Labile - continuously dividing; ex. epidermis and gastrointestinal, respiratory, urinary, and genital tract mucosa, bone marrow, and lymphoid tissue
*Stable - low level of replication usually, but can undergo rapid division in response to tissue injury; ex. endocrine, endothelium
*Permanent - nondividing, cannot undergo mitotic division postnatally; ex. neurons, cardiac myocytes, lens cells |
|
|
Term
| Define cell-matrix interactions and explain why they are important. |
|
Definition
| The physical contact between cells and their surrounding extracellular matrix. The structural and functional integrity of normal mature tissues depends on a close relationship between cells and their surrounding connective tissue matrix. Cell migration and differentiation during wound healing also depends on this integrity. |
|
|
Term
| Explain how cytokines function and list five examples of cytokines. |
|
Definition
| Cytokines are soluble proteins that bind to specific cell surface receptors, and stimulate mitogenic growth factors in order to modulate cell behavior; ex. Macrophage-derived Growth Factor, Platelet-derived Growth Factor, Epidermal Growth Factor, Fibroblast Growth Factor, and Transforming Growth Factor-B. |
|
|
Term
| Describe the three mechanisms of wound healing that operate simultaneously after the inflammatory phase. |
|
Definition
*Contraction - inward migration of surrounding mesenchymal cells causes an initial reduction in the size of a 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, cell proliferation, and collagen synthesis
*Regeneration - missing cells are replaced by new ones |
|
|
Term
| Differentiate between healing of wounds by primary and secondary intention. |
|
Definition
*Primary - healing of a clean incision with approximated (apposed) wound edges
*Secondary - occurs with more extensive loss of tissue or failure to approximate edges |
|
|
Term
| List four local factors that influence wound healing. |
|
Definition
*Type, size and location of wound
*Vascular supply
*Infection
*Movement |
|
|
Term
| List four systemic factors that influence wound healing. |
|
Definition
*Circulatory status
*Infection
*Metabolic status
*Nutritional status |
|
|
Term
| Discuss two factors that would lead to deficient scar formation. |
|
Definition
*Would dehiscence (bursting of a wound) - most common after abdominal surgery due to increased mechanical stress from abnormal movements such as vomiting, coughing or from systemic factors that predispose such as poor metabolic status
*Ulceration - due to inadequate intrinsic blood supply to injured area |
|
|
Term
| Describe keloids and contractures. |
|
Definition
*Keloid - excessive deposition of extracellular matrix resulting in a hypertrophic scar
*Contracture - exaggerated healing causing deformity of wound and surrounding tissue |
|
|
