1 / 37

Chapter 3 Connective tissue

Chapter 3 Connective tissue. 1. General features: 1) small number of cells and large amount of extracellular ground substance 2) extracellular is composed of fibers and amorphous ground substance-matrix 3) all of them originate from mesenchyme-embryonal CT

fritz-moran
Download Presentation

Chapter 3 Connective tissue

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Chapter 3 Connective tissue

  2. 1. General features: 1)small number of cells and large amount of extracellular ground substance 2) extracellular is composed of fibers and amorphous ground substance-matrix 3)all of them originate from mesenchyme-embryonal CT 4) have functions of connection, supporting, protecting, nutrition, defence and repairing

  3. mesenchyme ---mesenchymal cell: /structure: • stellate in shaped with processes • a large nucleus,with clear nucleoles • slight basophilic cytoplasm /function: a. undifferentiated cell b. multiple developmental potential→CT cell, SM and endothelial cell ---matrix

  4. 2.Classification ---CT in narrow sense means connetive proper which include loose CT, dense CT, adipose T and reticular tissue ---CT in wide sense includes cartilage, bone and blood

  5. 3.Loose connective tissue(areolar tissue) • features: have more types of cells and less fibers • functions: connection,supporting,defence and repairing • consists of cells, fiber and ground substance

  6. cells:seven types of cells are present in LCT

  7. ① fibroblast ---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

  8. EM: • rich in RER,Golgi appatatus and free ribosome ---function: synthesize fibers and ground substance

  9. Synthesis of collagenous fiber Three steps: a.synthesis of procollagen(RER) → process(Golgi) → out of cell b.procollagen→ tropocollagen → fibril c.fibril → collagenous fiber

  10. *fibrocyte: still state or inactive fibroblast ---structure: • spindle-shaped, small • N:small,dark stained • Acidophilic cytoplasma • EM: less organelles ---function: become into fibroblast for repairing

  11. ②macrophage ---structure: LM: • round or ovoid-irregular in shape when it have short blunt processes_pseudopodium • Small and dark nucleus • Acidophilic cytoplasm

  12. EM: rich in • a.lysosome • b.Phagosome← phagocytosis and • pinosome ←pinocytosis • c.Remnant • d.Microfilament and microtubule

  13. ---function: a.Chemotaxis: chemotactic factor b. phagocytosis: • Special phagocytosis: recognize Bacterium, virus and foreign cell • non special: carbon particles, dust and dead cells *Phagosome(pinosome) + primary lysosome →secondary lysosome →remnants

  14. c.secretion: lysozyme, complement and interleukin-I (IL-1)and interferon(INF) b.antigen presenting function: *capture antigen→processes→+ MHC II molecule (major histocompatibility complex molecules) →antigen-MHC II complexes→TLC

  15. ③plasma cell ---structure: LM: • round or ovoid • Round eccentrically-located nucleus with more spot-liked heterochromatin • Basophilic cytoplasm

  16. EM: rich in parallelly arranged RER, free ribosome and Golgi complex ---function: synthesize and secrete immunoglobulin, Ig-antibody

  17. ④mast cell ---structure: LM: • round and large cell • Small dark-stained nucleus • Basophilic secreting granules

  18. Basophilic secreting granules: • heparin:an anticoagulant • Histamine: cause cap. permeability↑, cap. leakage to form oedema and contraction of SM • Eosinophil chemotactic factor Cytoplasm contain: • leukotriene- slow reaction substance ---function: cause allergic reaction

  19. ⑤fat 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

  20. ⑥undifferentiated mesenchymal cell ---structure:similar to fibrocyto ---function:multidifferentiating potential ⑦leukocytes: neutrophil,acidophil and lymphocyte

  21. 2) fibers

  22. ①collagenous fiber(white fiber) LM: • 1-20 um in diameter • Belt-liked wave and branch to form a network • Eosinophilic

  23. EM: parallel-arranged fibrils Fibril: • 20-200nm in diameter • Have periodic cross striation at 64nm interval *formation: Extracellular polymerize collagen(type I and III) →collagenous fibril → collagenous fiber

  24. ② elastic fiber (yellow fiber) LM: • thinner and less, 0.2-1.0 um • Slight red(HE), purple(aldehyde fuchsin) or brown(orcein) • Branch and form a network EM: • core: elastin-low electron density • Peripheral: microfibril 10-12 nm, electron dense ↑ fibrillin

  25. ③reticular fiber 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

  26. 3) ground substance ---amorphous colloidal substance ---consists of proteoglycan, glycoprotein and tissue fluid

  27. ①proteoglycan-large molecular complex ---glycosaminoglycans: • chondroitin sulfate • keratin sulfate • dermatan sulfate • heparin sulfate • hyaluronic acid: 2.5um long --protein *molecular sieve

  28. ② glycoprotein: proteins ---fibronectin cells←fibronectin→collagen ↓ proteoglycan ---laminin ---chondronectin ---function: • Connection • affect the differentiation and movement of cells

  29. ③ tissue fluid tissue artery → Tissue fluid → vein →blood steam cells • dehydration • oedema

  30. 4.Dense connective tissue ---more fiber ---connection and supporting

  31. 1) regular DCT: • parallelly-arranged collagenous fibers • tendon cells: /special fibroblast /wing-liked processes ---distribution: tendons, ligament and cornea

  32. 2) irregular DCT: • Fiber arranged in bundles,runing in different direction • Fibroblast • less ground substance ---distribution: dermis, sclera and capsule of some organs

  33. 3) elastic T: • elastic fiber in bundles or in membrane • ligament and large artery

  34. 5.adipose tissue ---LCT+fat cells ---white fat T: • single fat cell • distribution in subcutaneous tissue, mesenterium ---brown fat T: • fat cell contain many small lipid droplets, • rich in large mitochondria • centrally-located nucleus • rich in cap. • distribution: neonate

  35. 6.reticular tissue ---reticular cells: • stellate 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

More Related