损伤的修复,损伤(injury)缺损(defect)修复(repair),修复(repair),机体对损伤所形成缺损进行修补恢复的过程。 Repair is a response to tissue injury and the process to restore integrity to an injured tissue by the organism.,问题与启迪(questions),什么是瘢痕？ 瘢痕是怎样形成的？ 能不能不形成瘢痕？ 瘢痕形成有正面意义吗？ 能否加速伤口愈合？ 伤口愈合不佳的原因有哪些？,修复形式(Types of repair),1.再生(regeneration):同种组织完全再生Repair by same tissue 2.纤维性修复(fibrous repair) 纤维结缔组织修复Replacement by fibrous tissue,第一节 再生 （Regeneration）,P27,定义:由损伤部周围的同种细胞来修复，称为再生(regeneration) Repair by cells of same type 特点:完全恢复原组织的结构及功能,Whats regeneration?,一 组织的再生能力 (Regenerative potentials of tissues),低等动物 高等动物 分化低 分化高 易受损伤和常更新组织再生能力强 取决于动物的种类和组织分化能力 生物进化(evolution),一 细胞再生能力分类(Types),1.不稳定细胞(labile cells) 强再生能力;表皮,粘膜上皮,间皮,淋巴及造血细胞 Continuously dividing and dying Covering epithelia Hematopoietic cells(the bone marrow cells and the lymphoid cells),2.稳定细胞(stable cells),较强再生能力, 肝,胰,肾,腺体,平滑肌,原始间叶细胞及其分化细胞(纤维母,软骨,骨母) Quiescent but can rapidly divide in response to injury Parenchymal of solid glandular tissues: liver, kidney, pancreas, gland Endothelial cells Connective tissue (fibroblast, osteoblasts) Smooth muscle,3.永久性细胞(permanent cells),微弱或无再生能力; 神经元,骨骼肌,心肌细胞 Be terminally differentiated and nonproliferative after the growth early in life Nerve cells(neuron), striated and cardiac muscle cells,1. Labile cells: continuouslydividing cells,2. Stable cells: quiescent cells that divide only when needed,3. Permanent cells: nondividing cellsthat permanently removed from cell cycle,小结(Summary):细胞再生力分类,二 组织的再生过程(Regeneration of various tissues),1被覆上皮(covering epithelia)基底细胞分裂增生,2腺上皮(glandular epithelia)BM未破坏完全再生BM破坏不完全再生(reticulin scaffold ),Regeneration of various tissues,3.血管(blood vessel) 小血管及毛细血管内皮出芽(sprout) -实性条索血流冲击-形成管腔(canalization) 大血管内皮(endothelial cells )-完全再生肌层(smooth muscles):-疤痕修复,Regeneration of various tissues,4.神经组织(nervous tissue) (1)脑及脊髓神经细胞(nerve cell)胶质瘢痕(glial scar) 新知识点：可再生！,4.神经组织(nervous tissue),(2)外周神经(peripheral nerve) 可完全再生 髓鞘及轴突崩解 神经鞘细胞增生 轴突延长 1mm/Day,创伤性神经瘤,Traumatic neuroma,三 细胞再生的分子机制,1.干细胞(stem cell) 具有自我更新和分化潜能的未分化细胞 自我更新(Self-renewal) 分化潜能(Differentiation) 不对称复制(asymmetric replication) 前体细胞/特化细胞precursors/specialized cell,新概念: 再生医学,Regenerative Medicine 胚胎干细胞(Embryonic stem cells, ESC) : pluripotent cells Therapeutic cloning,成体干细胞(Adult Stem cells, ASC) :More restricted differentiation capacity Bone Marrow Haematopoietic stem cells,新概念: 再生医学,新概念: 再生医学,诱导性多能干细胞（iPSC）(induced pluripotent stem cells) :已分化成体细胞的重新编程,细胞再生与分化的分子机制,2.细胞外基质(ECM)(Extracellular Matrix)胶原纤维,弹力纤维,粘附蛋白,蛋白多糖, 3.信号转导(Signal transduction) 4.细胞因子/生长因子(Cytokine/growth factor),Growth factors & cytokines,PDGF-platelet derived growth factor FGF-fibroblast growth factor EGF-epidermal growth factor TGF-transforming growth factor VEGF-vascular endothelial growth factor NGF- nerve growth factor HGF-hepatocyte growth factor TNF-tumor necrosis factor IL-1interleukin-1(白细胞介素-1),细胞再生与分化的分子机制,5.接触抑制(contact inhibition) 6.抑素(chalone) 7.基因调控(gene regulation)原癌基因(proto-oncogene)细胞周期基因(cell division cycle genes, CDC genes),第二节 纤维性修复(Fibrous repair),P36,纤维性修复,瘢痕修复(Scar repair) 再生能力弱或缺乏再生能力的组织(less regeneration capacity)； 无原组织的结构及功能 不完全修复(incomplete repair),纤维性修复特点 Features of fibrous repair,肉芽组织（granulation tissue),pink, soft, wet and granular,一 肉芽组织(granulation tissue),由新生的毛细血管、增生的纤维母细胞和各种炎性细胞组成,呈鲜红色,颗粒状,柔软湿润,形似鲜嫩的肉芽 Fibroblasts and new capillaries in a loose extracellular matrix.,Granulation tissue: morphology,新生毛细血管,垂直于创面 Richly capillary sprouts 纤维母,肌纤维母细胞 Reactive fibroblasts and myofibroblasts 炎细胞:中性粒,巨噬,淋巴细胞 Variable numbers of inflammatory cells,Granulation tissue: function,抗感染及保护创面Anti-infection and protect the wound surface 填补伤口及组织缺损To make up the deficiency and repair the injured tissue 机化或包裹坏死、血栓、炎症渗出物及异物To organize blood clotting, necrotic tissues or abnormal substances转化 疤痕组织(scar),二 瘢痕组织(scar tissue),瘢痕组织是肉芽组织逐渐成熟(纤维化)并老化（玻璃样变）的纤维结缔组织。 Fibrosis/maturation and retrogradation of granulation tissue Pale-gray, hard, lack of elasticity, tissue shrinkage,瘢痕组织形态(morphology),毛细血管退化消失(blood capillary) 纤维母细胞/纤维细胞稀少(fibroblasts) 炎细胞消失(inflammatory cells) 胶原纤维大量平行交错(collagen synthesis) 间质致密玻璃样变(hyaline change),瘢痕组织的作用(function),有利(advantages)填补创伤缺损,保持组织器官完整性Integrity: fill the defect and repair the tissue瘢痕中胶原纤维具有一定抗拉力,保持组织的坚固性。Firmness: more tensile strength,Complications of Scar -Excessive scar formation,不利(disadvantages) 瘢痕收缩(Scar contractures):关节挛缩(joint contracture),瘢痕粘连(Adhesions): 肠粘连,器官硬化(Sclerosis): 肺纤维化,Complications of Scar,肥大性瘢痕(Hypertrophic Scar):,瘢痕疙瘩（keloid) 蟹足肿(cheloid),瘢痕体质 (genetic predisposition) III型胶原(Deposition of Type III collagen),Complications of Scar,第三节 创 伤 愈 合 (Wound healing),P40,创伤愈合(wound healing) 是指机体遭受外力作用，皮肤等组织出现离断或缺损后的愈复过程。 A complex but orderly process, involving both parenchymal cells regeneration and the formation of connective tissue scar.,Whats wound healing?,一 创伤愈合的基本过程 (Basic process of wound healing),1.伤口早期变化(exudate) 2.伤口收缩(contraction of the wound):2-3d 3.肉芽组织和瘢痕形成(granulation & mature) 4.表皮等组织再生(regeneration),