1. Connective tissue Jun Zhou ( 周俊 ) School of Medicine, Zhejiang University 20140408

2. General features small number of cells and large amount of extracellular ground substance no polarity vascularized originate from mesenchyme （间充质） -embryonic CT Function: connection, supporting, protecting, nutrition, defence and repairing

3. Mesenchyme （间充质） ---mesenchymal cell: Structure:  stellate in shaped with processes  a large nucleus,with clear nucleolus  slight basophilic cytoplasm Function:  undifferentiated cell  multiple developmental potential →CT cell, SM and endothelial cell ---matrix

4. Classification ---CT in narrow sense means connetive tissue proper （固有结缔组织） which include loose CT, dense CT, adipose T and reticular tissue ---CT in wide sense includes cartilage ( 软骨 ), bone and blood

5. cartilagebone blood

6.  Features: more types of cells, less fibers  Functions: connection, supporting, defence and repairing  consists of cells, fiber and ground substance Loose connective tissue （疏松结缔组织） (areolar tissue)

7. Fibers 1. Collagenous fibers （胶原纤维） 2. Elastic fibers （弹性纤维） 3. Reticular fibers （网状纤维）

8. LM:  1-20 um in diameter  Belt-liked wave and branch to form a network  Eosinophilic Collagenous fiber （胶原纤维） (white fiber)

9. EM: parallel-arranged fibrils Fibril （原纤维） : 20-200nm in diameter Have periodic cross striation at 64-70nm interval

10. LM: thinner and less, 0.2-1.0 um Slight red (HE) branch and form a network EM: core: elastin-low electron density Peripheral: microfibril ( 微原纤维 )10-12 nm, electron dense ↑ fibrillin( 原纤维蛋白 ) Elastic fiber （弹性纤维） (yellow fiber)

11. LM: thin and less,0.2-1.0 um in diameter, branch to form network Argyrophilic fiber (silver impregnation method) EM: type III collagen 64nm cross striation Distribution: reticular tissue connecting portion, e.g.reticular lamina Reticular fiber （网状纤维）

12. Ground substance （基质） --- amorphous colloidal substance ---consists of proteoglycan （蛋白多糖）, glycoprotein （糖蛋白） and tissue fluid

13. ① Proteoglycan （蛋白多糖） -large molecular complex ---glycosaminoglycans （糖胺多糖） chondroitin sulfate （硫酸软骨素） keratin sulfate （硫酸角质素） heparan sulfate （硫酸乙酰肝素） hyaluronic acid （透明质酸） : 2.5um long --protein * molecular sieve ( 分子筛 )

14. ② Glycoprotein （糖蛋白） : proteins ---fibronectin ( 纤维粘连蛋白 ) ---laminin ( 层粘连蛋白 ) ---chondronectin ( 软骨粘连蛋白 ) ---Function:  Connection  affect the differentiation and movement of cells

15. ③ tissue fluid （组织液） tissue artery → Tissue fluid → vein (lymphatic vessel) cells Dehydration （脱水） Edema （水肿）

16. Molecular sieve ( 分子筛 ) Function: 1.Provides mechanical and structural support for metabolism 2.Influences extracellular communication 3.Limitation of inflammation

17. Cells Resident Fibroblasts (Fibrocytes) （成纤维细胞） Macrophages (Histiocytes) （巨噬细胞） Plasma cells （浆细胞） Mast cells （肥大细胞） Adipocytes （脂肪细胞） Stem Cells （干细胞） (committed but not differentiated) Transient Nucleated Blood Cells (Lymphocytes, Plasma Cells, Eosinophils- others occasionally )

18. ---Structure: LM:  Large,flattened cell with processes- stellate in shaped  Large ovoid pale nucleus-contain more fine chromatin, with clear one-two nucleoli  Weakly basophilic cytoplasm-homogeneous Fibroblast （成纤维细胞）

19. EM:  rich in RER, Golgi apparatus and free ribosome Function: synthesize fibers and ground substance

20. Three steps: a.synthesis of procollagen (RER) → process(Golgi) → out of cell b.procollagen→ tropocollagen → fibril c.fibril → collagenous fiber Synthesis of collagenous fiber ( 前胶原蛋白 ) ( 原胶原蛋白 ) ( 胶原原纤维 )

21. Fibrocyte ( 纤维细胞 ): inactive fibroblast ---Structure: spindle-shaped, small N:small,dark stained Acidophilic cytoplasma EM: less organelles ---Function:: become into fibroblast for repairing

22. From monocytes ---Structure: LM: round or ovoid-irregular in shape ， short blunt processes pseudopodium( 伪足 ) Small and dark nucleus Acidophilic cytoplasm Macrophage ( 巨噬细胞 )

23. EM: rich in Lysosome (primary, secondary) Phagosome( 吞噬体 )← phagocytosis and pinosome ( 吞饮小泡 )←pinocytosis Remnant Microfilament and microtubule Mitochondria

24. ---Function:  Chemotaxis: chemotactic factor  Phagocytosis: 1) Special phagocytosis: recognize bacterium, virus and foreign cell 2) non special: carbon particles, dust and dead cells  Secretion: lysozyme, complement and interleukin-I (IL-1)and interferon(IFN)  Antigen presenting function

25. Mature B lymphocyte ---structure: LM: round or ovoid Round eccentrically-located nucleus with more spot- liked heterochromatin Basophilic cytoplasm Plasma cell （浆细胞）

26. EM: RER, free ribosome and Golgi complex Function:  synthesize and secrete immunoglobulin, Ig-antibody

27. ---structure: LM: round and large cell Small dark-stained nucleus Basophilic secreting granules Metachromatic 异染性 Mast cell （肥大细胞）

28. Basophilic secreting granules:  heparin: an anticoagulant  Histamine: cause cap. permeability↑, cap. leakage to form edema and contraction of SM  Eosinophil chemotactic factor Cytoplasm contain: slow reaction substance --Function: involved in allergic reaction

29. Fat cell ---structure:  large, round or polygonal  flattened ovoid nucleus located on one side of cell  thin layer of cytoplasm  a large lipid droplet ---function: synthesize and store fat Mesenchymal cell  similar to fibrocyte  multidifferentiating potential Leukocytes: neutrophil, acidophil and lymphocyt e

30. Dense connective tissue （致密结缔组织） ---more fiber ---connection and supporting

31. 1) Regular DCT:  parallelly-arranged collagenous fibers  special fibroblast wing-liked processes ---Distribution: tendons, ligament, cornea

32. 2) Irregular DCT:  Fiber arranged in bundles, running in different direction  Fibroblast  less ground substance ---Distribution: dermis, sclera,capsule of some organs

33. Adipose tissue （脂肪组织） --- LCT+fat cells ---White fat T: single fat cell Distribution: subcutaneous tissue, mesenterium ---Brown fat T: fat cell contain many small lipid droplets, rich in large mitochondria centrally-located nucleus rich in cap. Distribution: newborn baby

36. Reticular tissue （网状组织） ---Reticular cells + Reticular fiber + Stroma ---Reticular cells:  Irregular with processes-form network  round, ovoid and pale nucleus with 1-2 nucleoli  EM: rich in RER ---Reticular fiber: connect to form network ---Distribution: hemopoietic tissue and lymphatic tissue

37. THE END!