1. Chapter 3 Connective tissue

2. 1.cells
extracellular matrix
2. Fibers
3.Ground substance
tissue fluid

3. 1.       General features:
1)   small number of cells and large amount of extracellular ground substance
2)  no polarity
3)   all of them originate from mesenchyme -embryonic CT
4) have functions of connection, supporting, protecting, nutrition, defence and repairing

4. 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

5. 2. Classification (1) CT in narrow sense means connetive
tissue proper which include:
loose CT
dense CT
adipose T
reticular tissue

6. (2) CT in wide sense includes :
cartilage
bone
blood

7. 3. Loose connective tissue (areolar tissue)
consists of cells, fiber and ground substance
features: have more types of cells and less fibers

8. functions: connection, supporting, defence and repairing

9. Cells:

10. ① fibroblast ---structure: LM:
large,flattened cell with processes- stellate in shaped
Large ovoid pale nucleus - contain more fine chromatin, with clear one or two nucleoli
Weakly basophilic cytoplasm

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

12. 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

13. fibroblast
fibroblast
fibrocyte
fibrocyte

14. ②macrophage ---structure: LM: Round, ovoid or irregular in shape
have short blunt processes: pseudopodium
Small and dark nucleus
Acidophilic cytoplasm

16. EM: rich in a. lysosome b. Phagosome: phagocytosis c. Remnant
d.  Microfilament and microtubule

17. a. Chemotaxis: chemotactic factor b. phagocytosis:
---function:
a.    Chemotaxis: chemotactic factor
b. phagocytosis:
(1)Special phagocytosis: recognize bacterium, virus and foreign cell
phagocytosis

18. (2)non special phagocytosis: carbon particles, dust and dead cells

19. c.  secretion: lysozyme, complement and interleukin-I (IL-1)and interferon(INF)
d.     antigen presenting function

20. ③plasma cell
---structure:
LM:
round or ovoid
Nucleus with more spot-liked heterochromatin which located eccentrically
Basophilic cytoplasm

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

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

23. Basophilic secreting granules:
heparin: an anticoagulant
Histamine: cause cap. permeability↑, cap. leakage to form edema and contraction of SM
Eosinophil chemotactic factor

24. Cytoplasm contain:
slow reaction substance
---function: to cause allergic reaction

25. 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

26. ⑥undifferentiated mesenchymal cell
---structure: similar to fibrocyte
---function: multidifferentiating potential

27. ⑦leukocytes: neutrophil, acidophil and lymphocyte, ect.

28. 2) fibers

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

31. EM: parallel-arranged fibrils
20-200nm in diameter
Have periodic cross striation at 64nm interval

32. ② elastic fiber (yellow fiber)
LM:
thinner and less, um
Slight red (HE) branch and form a network
EM:
core: elastin-low electron density
Peripheral: microfibril nm, electron dense ↑
fibrillin

33. ③reticular fiber LM: thin and less,0.2-1.0 um in diameter
Branch to form network
Argyrophilic fiber (silver impregnation method)

34. EM:
type III collagen
64nm cross striation
---distribution:
reticular tissue
connecting portion, e.g.reticular lamina

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

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

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

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

39. 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

41. white fat T
brown fat T

42. 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