Chapter 2
Repair of
tissue
damage
repair of tissue damage
injury tissue and cells
abrasion
tissue loss
restore
repair
department of pathology
During repair,the injured tissue is
replaced
by regeneration of native parenchymal cells
completely restore
(completely regeneration)
by filling of the defect with fibroblast scar tissue
fibrous scar restore
(incompletely regeneration)
department of pathology
Section 1,Regeneration
one cell divided tow cells
physiological --- normal
pathological --- abnormal
department of pathology
1.cell cycle:
Successive phases of a cell
through its cycle of
replication are define with
reference to DNA synthesis
and cellular division.
department of pathology
M
G1
S
G2 G0
Cell cycle
department of pathology
cellular
division
department of pathology
2.Regeneration
capacity of cells:
divided into three groups
ⅰ, labile cells
ⅱ, stable cells
ⅲ, permanent cells:
department of pathology
permanent cells:
normally divide only during
fetal life and they cannot be
replaced when lose.
nerve cell
skeletal muscles cells
cardiac muscles cells
department of pathology
nerve cell
cardiac muscles cells
skeletal muscles cells
department of pathology
stable cells:
divide very infrequently under normal conditions,but are
stimulated to divide rapidly when such cells are lost.
Gland organs( Liver,Endocrine gland )
Bone
Fibrous tissue
Renal tubules
department of pathology
Renal tubule
Gland organs
Fibrous tissue
stable cells
department of pathology
labile cells:
proliferate continuously in
post-natal life,they have a
short life-span and a rapid ‘turnover’ time.
except ‘stable,permanent’
department of pathology
Section 2,fibrin repair
granulation tissue
granulation tissue is formed in
the early stage of connective
tissue,which consists new
capillary and fibroblast,with
inflammatory cells infiltrating,
department of pathology
Granulation tissue consist of…
1,New capillaries
2,New connective tissue
( fibroblast,myofibroblast,collagen)
3,Inflammatory cells
department of pathology
New capillary
Capillary
endothelial cells
Base membrane
Red cells
department of pathology
fibroblast
collagen
Fibrin cell
Fibroblast are
stimulated to
divide and to
secrete collagen
department of pathology
Granulation tissue department of pathology
Granulation
tissue
department of pathology
Granulation tissue
department of pathology
Granulati
on tissue
department of pathology
Myofibroblast
wound repair
tissue defect
may be reduced by 80%
Why?
myofibroblast
department of pathology
Myofibroblasts
display features and
functions of both
fibroblast and smooth
muscles cells,
department of pathology
Loss of mechanical tension
reduces myofibroblast
differentiation in granuloma
pouch tissue.
by confocal laser-scanning
microscopy
double-stained for -SMA
(red) and ED-A FN (green)
department of pathology
Function of granulation tissue:
1.anti-infection and to cover wound
surface
2,to fill the tissue loss and wound
3.organization and encapisulation
department of pathology
Section 3 Wound healing
? skin
The process of healing of a skin
wound depends on the size of the
defect.
healing by first intention
healing by second intention
healing under scab
department of pathology
healing
by first
intention
department of pathology
department of pathology
department of pathology
department of pathology
department of pathology
healing by
second
intention
department of pathology
healing under
scab
department of pathology
Healing of bone fracture
department of pathology
PDGF
TGF-β
platelet
fibronectin collagen
growth
++
EGF
nutrients
Factors mediating wound healing
PDGF
TGF-β
TGF-β
myofibroblast
++
Salivary EGF
IGF
Fibroblast
PDGF
12
34
5
6
7
8
9
10
11
12
department of pathology
Regeneration and
capacity of cells
Granulation tissue
brief summary
department of pathology