Repair 1: Introduction Flashcards
describe the 2 types of repair
Regeneration:
* replacement of Damaged tissue with new cells of same type
* With connective tissue and infrastructure (ECM) intact
* surviving cells must have the capacity to regenrate
Healing by fibrosis (scar):
* Replacement of damaged tissue by granulation tissue —> scar tissue
* due to sever damge of parynchymal organ/ infrastructure + surviving cells are non-dividing
examples of Regenration
- damage to epithelium
- minimal damage affecting only hepatocytes of liver
general factors influencing repair
- Age (- elderly)
- Malnutrition: - ptn & Vit. C –> -collagen synthesis
- Circulatory status (atherosclerosis)
- Drugs: glucocorticoid (cortisol) –> -TGFbeta
- DM & Anemia –
- hormones: Steroids -TGFbeta
Local factors influencing repair
- Extent of tissue damage
- Blood supply to site
- infection & foreign bodies
- site
- Mechanics (torsion & pressure)
- type of tissue
cells that continously prolifrate
Liable cells
Cells that prolifrate only under certain conditions
Stable cells
cells that do not prolifrate
permanent cells
examples of liable cells
- surface epithelium
- Lymphoid cells
- Hemopoeitic cells of bone marrow
Examples of Stable cells
Parenchymal:
* Liver
* kidney
* Pancreas
Mesenchymal:
* endothelium
* fibroblast
* osteoblast
* smooth muscles
examples of Permanent cells
- Skeletal muscles = heal by fibrosis (done by fibrobasts)
- Nerve cells= heal by gliosis (done by astrocytes/glial cells)
Mechanism of repair of Liable cells
regenration
Mechanism of repair of Stable cells
regenration or fibrosis
Stable cells have limited capacity to regenerate except for ____
Hepatocytes (liver)
Mechanism of repair of permanent cells
Fibrosis (skeltal muscle) & Gliosis (nerve cells)
Power of regeneration of liable cells
Short G0
High power
