回帖：Chapter 2 Tissue Repair
§1. Regeneration
·Complete regeneration
Incomplete regeneration: fibrous repair → scar
·Physiologic: cell renewing
Pathologic: cell injury → regeneration
1. Cell cycle and proliferative potential
(1)Cell cycle: Interphase: G1 (presynthetic)
S (DNA synthesis)
G2 (premitotic)
Mitotic phase (M)
Go: quiescent cells in a physiologic state
(2)Types
①Labile cells (continuously dividing cell)
Definition: continue to proliferate → replacing destroyed cells and aged cells
Cell groups: Stratified squamous cell: epidermis, oral cavity, vagina and cervix
The lining mucosa of respiratory and gastrointestinal tract
Epithelium of the male and female tract
Transitional epithelial of urinary tract
Hematopoietic and lymphoid cells
②Stable (quiescent) cells
Definition: not divide or at a very slow rate and undergo rapid division in response to injury
Cell groups: Parenchymal cells of glandular organ: liver, renal tubule epithelium
Mesenchymal cells: fibroblast, SMC
③Permanent (nondividing) cells
Definition: no capacity of regeneration
Cell groups: Nerve cells: Neurons destroyed are permanent, replaced by the proliferation of glial cell → glial scar
Skeletal muscle cells
Cardiac muscle cells
2. Regeneration process of various tissues
(1)Epithelial tissue
·Surface epithelium: Squamous cell → basal layer cell
Columnar cell → adjacent gland recess cell
·Glandular epithelium: Base membrane intact → restored cell
Base membrane destroyed → difficult
Liver: Resected partly → liver cell proliferation
Necrosis of liver cell, reticular framework intact → hepatocyte proliferation → restore the structure
Necrosis widely, reticular framework collapsed → hepatocyte nodular regeneration
(2)Fibrous tissue
(3)Blood vessel regeneration
·Capillary: budding
·Large blood vessel
(4)Cartilage and bone tissue
(5)Muscle regeneration
(6)Nervous tissue
§2. Fibrous repair
1. Granulation Tissue
①Composition: composed of numerous newly formed capillaries and fibroblast, accompanied with inflammatory cell infiltration
②Morphology: Gross: red, soft, granular appearance
LM: capillaries + fibroblast + inflammatory cells
③Functions: Anti-infection and protect wound surface from further injury
Filling wound and the detect area
Replacing or encapsule necrosis, thrombus, foreign bodies
2. Scar
①Morphology: Gross: contract, pallor, semitransparent, tough less elasticity
LM: composed of parallel collagen fascicle (hyaline change)
less fibrous cells and blood vessel
②effect and harm of scar
·benefits: filling the wound and ulcer, make tissue and organ intact
stronger resist pull, lack of elasticity → hernia
·disbenefit and harm: contract → obstruction
conglutination
excess hyperplasia → hypertrophic scar (keloid)
§3. Wound healing
1. process of wound healing
(1)early change: an acute inflammatory process by the initial injury
(2)contraction of wound
(3)proliferation of granulation tissue and formation of scar
(4)migration and regeneration of epithelium and other tissues
2. types of wound healing
(1)Healing by first intention (wounds with opposed edges)
a clean, uninfected surgical incision
(2)Healing by second intention (wounds with separated edges)
more extensive loss of cells and tissue, inflammatory ulceration, abscess formation
3. bone fracture healing
(1)basic process
·hematoma formation: 1-2days
·fibrous bone scab fo