Tissue repair

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Chapter 2

• Tissue repair

Department of pathology longjie
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Repair (??) Would healing (????)
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Repair (??)

• As cells and tissues are being injured, events
  that contain the damage and prepare the surviving
  cells to replicate are set into motion.

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• Repair begins very early in the cell injury,
  and involves two processes
• 1. Regeneration (??)
• 2. fibrosis (?????)

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regeneration
? ?

• Regeneration of injured tissue by
• parenchymal cells of the same type .

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types
Physiological regeneration Pathological
regeneration
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Proliferative potential of different cell types
?????
Labile cells
????
Stable cells
Permanent cells
?????
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Labile cells

• Continuously dividing and dying
• Surface epithelia
• stratified squamous surfaces
• cuboidal epithelia
• columnar epithlium
• transitional epithelium
• Hematopoietic cells

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Stable cells

• Quiescent but can rapidly divide in response to
  injury
• Parenchymal of solid glandular tissues liver,
  kidney, pancreas
• Endothelial cells lining blood vessels
• fibroblast
• Smooth muscle connective tissue

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Permanent cells

• Be terminally differentiated and nonproliferative
  in postnatal life
• neurons
• Cardiac muscle cells

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Regeneration of different tissues
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??????? angiogenesis
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fibrosis
?????

• Replacement by connective tissue, resulting
  in a scar.

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types
Granulation tissue (????) Scar
(??)
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• Gross pink , soft , granular

Granulation tissue

• Micro
• proliferation of fibroblasts
• new thin-walled, delicate capillaries
• inflammatory cells

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??????
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????
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Granulation tissue
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fibroblast
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signafication

• risist infection and protect the wound surface
• fill the deficiency and repair the injured
  tissue
• organize blood clotting, necrotic tissues or
  abnormal substances

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• Gross tissue shrinkage, pale-gray ,
• hard , lack of elasticity

scar

• Micro
• fibroblasts , new vessels
  avascular
• inflammatory cells
• collagen synthesis
  hyaline change

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effect
Good 1.fill the defect, repair the tissue
2. More tensile strength than granulation
tissue
bad 1.scar shrinkage obstruction of
tissue activity 2. Scaring
conglutination ( ?????) 3. Organ
cirrosis (????) 4. Scar
hyperplasia (????)
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Wound Healing
A complex but orderly process, involving both
parenchymal cells regeneration and the formation
of connective tissue scar.(????)
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Healing of skin wound

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types
Healing by first intention (primary
union)
????
Healing by second intention (sceondary
union)
????
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Healing of a clean , uninfected surgical incision
approximated by surgical sutures.
Healing by first intention
1. Less fibrinclotted blood, granulation tissue
and scar 2. Mild inflammation reaction
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? ? ? ? ? ? ?
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large tissue defects, infected and irregular
incision.
Healing by secondary intention
1. Much larger amounts of granulation tissue and
scar 2. Extensive inflammation reaction
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???????
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Healing of skin wound
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influences of healing
glucocorticoids
Mechanical factors
radiation
Age
infection
Blood supply
nutrition
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Healing of bone fracture (self study)

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