9. Wound Healing I Flashcards
WOUND HEALING
- Regeneration
- Replacement; same type. • Normal function.
• Scar formation:
• Replacement with connective
tissue (collagen, scar); ____
• Extensive deposition of collagen
• Chronic inflammation (Fibrosis)
• Loss of function;
____
Healing
Chronic Inflammation
Mechanisms of Fibrosis
- Persistent chronic injury leads to ____ (loss of tissue architecture)
- Cytokines produced mainly by ____ leads to migration of fibroblasts/myofibroblasts
- Deposition of collagen and other ECM proteins
- Fibrosis
Severe injury > inflammation > macrophages + T lymphocytes > TGFbeta, and other GF > activating ____
Myofibroblasts and the result of fibrosis
chronic inflammation
macrophages
fibroblasts
Cell types
Labile: tissue is damaged, the tissue will ____
Stable: tissue is damaged, it can either ____ or form a ____
Permanent: tissue is damaged, cannot regenerate, but will form a ____ and will result in a collagenous scar
regenerate
regenerate
scar
scar
Labile Cells
Tissue that contains 1.5-2% of labile cells > considered to contain labile cells
Cells are continuously ____, so if all were labile that would result in the formation of ____
Only a small ____; exist to replace damaged cells
dividing
cancer
proportion
Labile Cells
- Most surface epithelia:
- ____ surfaces:
- Skin, Oral Cavity, Vagina and cervix
- ____ of ducts of exocrine organs: • Salivary glands, pancreas, biliary duct
- ____ epithelia:
- GI, uterus and fallopian tube
- ____ epithelium:
- Urinary tract
- ____ in the bone marrow
stratified squamous cuboidal epithelia columnar transitional hematopoietic cells
Injury to cells? Do they always regenerate? Depends on extent of injury
When labile cells divide, it gives two daughters, one remains as a ____ and the other cell differentiates into an ____ cell
If injury is persistent, you won’t see injury
If damages the BM (where ____ cells reside) > no regeneration, will get ____ formation
____ > scratching, damaging BM > scar formation
SC
epithelial
labile cells
scar
chicken pox
Regeneration and Scar Formation
[NOTES]
Fracture of bone > high capacity to ____
But if BM infection > chronic inflammation > foci of inflammatory cells > ____ > lymphocytes + macrophages > ____ formation (no regeneration of bone)
regenerate
round-cells
scar
Stable Cells
Cells that are in the ____ phase (exited CC)
Not continuously ____; but do have the potential to divide if they are ____ to do so (in response to GF)
Important example: ____
Go
dividing
stimulated
liver
Stable Cells
Parenchymal cells of virtually all ____ organs of the body:
– ____
– Kidney
– ____
• Connective tissue and mesenchymal cells:
– ____
– smooth muscle cells
– ____ cells
glandular liver pancreas fibroblasts endothelial
Injury to cell matrix > chronic ____ > scar formation > liver has undergone ____
alcoholism
fibrosis
Human Liver has remarkable capacity to regenerate; 2 mechanisms
Resection of up to 90% of liver can be corrected by the proliferation of ____
In chronic injury or inflammation ____ in the liver contribute to regeneration
residual hepatocytes
progenitor cells
Kidney Regeneration
Right: kidney undergone chronic inflammation and stain with trichrome > ____ formation, it would look blue (glomeruli, not much in tubules, bc the ____ have a greater capacity to regnerate than the ____ (glomeruli undergoes fibrosis))
Acute inflammation: tender, ____ because of fluid, ____
scar tubules glomeruli larger pallor
Lung Regeneration
• left: normal lung
• 2nd left: ____ inflammation. alveolar septa filled w/ fluid/cells
◦ if it does not affect Fx of lung then it’s healing.
• 3rd: what happens if someone is exposed to ____ particle for a long period of time? as a result the lung
undergoes ____. H&E stain showing a lot of pink. ◦ ____ inflammation/____
• 4th: trichrome shows collagen.
acute silica fibrosis chronic LOF
Permanent Cells
- Cannot replicate after ____ .
- ____ , ____ muscle, ____ muscle.
- Once destroyed, they are lost ____ .
if you have a MI, then no attempt to regenerate cells b.c myocardial cells are ____ . If a tissue is made up of permanent cells then it is most likely to undergo ____ . there are some cells that can regenerate, but w/e cells there are they aren’t significant in # to promote healing. You can predict how tissue will heal based upon their ____ (____ has greatest capacity).
birth neurons skeletal cardiac for ever
permanent cells
fibrosis
composition
liver
Organized exudate > fibrosis forms on top of it > scarring (____, and if purulent originally: ____)
Acute inflammation, and etiology is not destroyed > \_\_\_\_: \_\_\_\_ cells (myocard) > scarring
Labile or stable cells > framework intact > resolution of normal ____ (____ pneumonia); if framework destroyed > ____
pericarditis
fibropurulent
necrosis
permanent
normal structure
lobar
scarring/fibrosis
