Chapter 2 Tissue repair Department of pathology longjie

Repair (修复） Would healing （创伤愈合）

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

Repair begins very early in the cell injury, and involves two processes: 1. Regeneration (再生） 2. fibrosis （纤维性修复）

regeneration 再 生 Regeneration of injured tissue by 再 生 Regeneration of injured tissue by parenchymal cells of the same type .

types Physiological regeneration Pathological regeneration

Proliferative potential of different cell types Labile cells 不稳定细胞 稳定细胞 Stable cells Permanent cells 永久性细胞

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

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

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

Regeneration of different tissues

毛细血管的再生 angiogenesis

fibrosis 纤维性修复 Replacement by connective tissue, resulting in a scar.

types Granulation tissue (肉芽组织) Scar (瘢痕)

Granulation tissue Gross: pink , soft , granular Micro: proliferation of fibroblasts new thin-walled, delicate capillaries inflammatory cells

脚的肉芽组织

肉芽组织

Granulation tissue

fibroblast

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

scar Gross: tissue shrinkage, pale-gray , hard , lack of elasticity Micro: fibroblasts , new vessels avascular inflammatory cells collagen synthesis hyaline change

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 ( 瘢痕性粘连） 3. Organ cirrosis （器官硬化） 4. Scar hyperplasia （瘢痕增生）

A complex but orderly process, involving both parenchymal cells regeneration and the formation of connective tissue scar.(创伤愈合) Wound Healing

Healing of skin wound

types Healing by first intention (primary union) 一期愈合 Healing by second intention (sceondary union) 二期愈合

Healing by first intention 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

一 期 愈 合 模 式 图

Healing by secondary intention large tissue defects, infected and irregular incision. Healing by secondary intention 1. Much larger amounts of granulation tissue and scar 2. Extensive inflammation reaction

二期愈合模式图

Healing of skin wound

influences of healing glucocorticoids Mechanical factors radiation Age infection Blood supply nutrition

Healing of bone fracture (self – study)

thanks!