1. Connective Tissues By Prof. Dr. Ashraf Mahmoud

2. Characters of C.T: Mesodermal. Blood vessels & nerve can penetrate it. Cells are widely separated. Formed of: Cells, fibres and soft ground substance.

3. New classification New classification Free 1- Free macrophages. 2-Plasma cells. 3-Mast cell. 4-Plasma cell. 5-Leukocytes. * Non stable *short lived *motile Fixed 1 - Fibroblast. 2 -Fixed macrophages. 3- Fat adipose cells. 4 -U.M.C. 5- Pericytes. 6 -Endothelial cells. 7 Reticular cells. *stable *long lived *non motile

4. Classification of C.T. Fibres: 1-White collagenus bundle. 2-Yellow elastic fibres. 3-Reticular fibres.

5. (c ) Different types of C.T. proper: 1-Loose areolar C.T. 2-White fibrous C.T. 3-Elastic C.T. 4-Reticular C.T. 5-Mucoid C.T.. 6-Fatty adipose C.T.

6. 3- Histiocytes, Macrophages or Phagocytes: They are irregular cells with blunt long processes, Macrophages can be demonstrated by vital staining They are irregular cells with blunt long processes, Macrophages can be demonstrated by vital staining

7. Function: They engulf dead neutrophilic leucocytes and bacteria by a phagocytes surrounding the object forming multinucleated foreign body giant cell. They engulf dead neutrophilic leucocytes and bacteria by a phagocytes surrounding the object forming multinucleated foreign body giant cell. Marcophages increase in number in chronic inflammation by: Marcophages increase in number in chronic inflammation by: 1- Multiplication of already present macrophages.

8. 4-Pigment Cells or Melanocytes 4-Pigment Cells or Melanocytes They are small branching cells rich in melanin pigments with a small centrally situated nucleus. They are small branching cells rich in melanin pigments with a small centrally situated nucleus. They are found in the skin, eye (retina, iris and choroid) and in substantia nigra of midbrain. They are found in the skin, eye (retina, iris and choroid) and in substantia nigra of midbrain.

9. Function: They carry melanin pigment which protect the body from the injurious effect of the sun. They carry melanin pigment which protect the body from the injurious effect of the sun.

10. [A] Undifferentiated cells 1) U.M.C. 2) Pericytes 3) Reticular cells Site C.T. of embryo. Around the capillaries Stroma of different organ Shape Small branched cell. - N: large, pale & oval. - C: pale basophilic Branched cell with - N: large, pale & oval - C: pale with few organelles Branched cells; together with reticular fibres form reticulum. function 1) Can differentiate into other C.T. cells. 2) In bone marrow form all blood cells. 1) Same function of U.M.C. but after birth. 2) 2) Their contraction → vasoconstriction 1) Support organs & glands. 2) On need has phagocytic function 3) In bone marrow give blood cells.

11. B- Rounded C.T. Cells B- Rounded C.T. Cells 1-Plasma cells They are irregularly ovoid in shape, small and centrically nucleus. They are irregularly ovoid in shape, small and centrically nucleus. The nuclear chromatin is concentrated towards the nuclear membrane in a regular manner giving it a “cartwheel” appearance. The nuclear chromatin is concentrated towards the nuclear membrane in a regular manner giving it a “cartwheel” appearance.

12. The cytoplasm is basophilic with a pale area representing Golgi apparatus “Negative Golgi image”. The cytoplasm is basophilic with a pale area representing Golgi apparatus “Negative Golgi image”. The cytoplasm of the plasma cells contains acidophilic inclusions known as RUSSEL BODIES. The cytoplasm of the plasma cells contains acidophilic inclusions known as RUSSEL BODIES.

14. Functions: Plasma cells are originated from B- lymphocytes: Plasma cells are originated from B- lymphocytes: B-lymphocytes antigen_ plasmablasts  plasma cells. B-lymphocytes antigen_ plasmablasts  plasma cells. Plasma cells produce the circulating antibodies and they are responsible for immune response. Plasma cells produce the circulating antibodies and they are responsible for immune response.

15. 2-Mast Cells 2-Mast Cells They are large ovoid cells with ovoid nuclei. They are large ovoid cells with ovoid nuclei. Cytoplasm is full of basophilic granules. Cytoplasm is full of basophilic granules. These granules are water soluble and are These granules are water soluble and are metachromatically stained by toluidine blue, so they are stained purple Mast cells are present in loose C.T. in relation to blood vessels. Mast cells are present in loose C.T. in relation to blood vessels.

16. Functions: Functions: -Secrete heparin (anticoagulant), -Secrete heparin (anticoagulant), -Secrete histamine, which participates in antigen antibody reaction. -Secrete histamine, which participates in antigen antibody reaction. -May have a role in serotonin secretion which, is a vasoconstrictor substance. -May have a role in serotonin secretion which, is a vasoconstrictor substance.

17. 3- Fat Cells 3- Fat Cells They are rounded or oval cells with flattened peripheral nuclei and thin rim of cytoplasm, containing large fat droplets. They are rounded or oval cells with flattened peripheral nuclei and thin rim of cytoplasm, containing large fat droplets. In H&E sections, the fat dissolved leaving an empty space and giving the appearance of a “signet”. In H&E sections, the fat dissolved leaving an empty space and giving the appearance of a “signet”. The fat cells can be stained orange with Sudan III and black with Sudan black. The fat cells can be stained orange with Sudan III and black with Sudan black.

19. Function: They support vital organs as the kidney. They support vital organs as the kidney. They store fat, which is the main source of energy. They store fat, which is the main source of energy. They decrease loss of heat from the skin. They decrease loss of heat from the skin.

20. Macrophages Plasma cells Mast cells Leucocyte OriginMonocytes Β- lymphocytes Β- lymphocytesU.M.C Migrated from blood Site Loose C.T. Lymphatic tissue Around blood vessel Shape * Large branched cells with pseudopodia - N: small,dark & kidney shape. - C: basophilic, non- clear (rich in lysosomes & phagocytic vesicles). * Small oval cell with - N: eccentric round with cart wheel or clock fore appearance. - C: deeply basophilic rich in: mit.,r-ER & * Oval cell with central round nucleus. -C: basophilic & have granule which are metachromaticlly stained Toluidine blue.. Neutrophils appear in acute infection. Eosinophils ↑↑in allergic & parasitic disease lymphocytes & monocytes ↑↑ in chronic infection. ↑↑ in chronic infection. Function Phagocytose any foreign Clean wounds from Antigen presenting cells. Secrete Antibodies. Secrete heparin anticoagula n. Secrete histamine allergy

21. Fibers Connective Tissues

22. Classification of C.T. fibres: 1-White collagen us bundle. 2-Yellow elastic fibres. 3-Reticular fibres.

23. A-White or Collagen Fibers About 1-20 µm formed of thick backed fibres forming groups of bundles closely arranged together. About 1-20 µm formed of thick backed fibres forming groups of bundles closely arranged together. Collagenous bundles are elastic -long- cylindrical appearance. Collagenous bundles are elastic -long- cylindrical appearance. Mainly located in Mainly located in Tendon. Tendon. Joint capsule. Joint capsule. Deep fascia. Deep fascia.

25. B-Yellow or Elastic Fibres B-Yellow or Elastic Fibres - They are thinner than collagen fibres, refractile.can branch, anastmose and are highly elastic. - They are thinner than collagen fibres, refractile.can branch, anastmose and are highly elastic. -They occur as fenestrated lamellae in arteries, and they can be stained brown with orcein, blue with Mallory and yellow with van Geison. -They occur as fenestrated lamellae in arteries, and they can be stained brown with orcein, blue with Mallory and yellow with van Geison.

26. C-Reticular Fibres - They are fine branching fibres stain brownish black with silver. - Function: - They participate in the stroma formation of - many organs as the kidney, liver and lung.

27. Comparison between the different types of C.T. fibers

28. Collagenous fibers Elastic fibers Reticular fibers Diameter Fiber 1-20 um fibril 75nm Fibrils14 nm 0.5-2um Shape Closely packed Irregular networks Form extensive networks Stains 1-Eosin= Pink 2-allory=Blue1-Orcein=Brown 1-Silver= dark brown brown Chemicall Collagen type I Collagen type III Boiling Form soft Gelatin Digestion Digested by elastase Main sites Tendon and ligament Blood vessels,lung Body organs ContainsGlycine,Proline Desmosine and isodesmosine

29. II- C.T. Proper

30. 1-Loose Areolar C.T. - It contains all the elements of C.T. -Cells mainly fibroblasts and histiocytes. -Cells mainly fibroblasts and histiocytes. Fibres mainly collagen and ground substance. found in : -Dermis of skin. -Dermis of skin. -Adventitia of blood vessels. -Adventitia of blood vessels. -Under epithelial membranes. -Under epithelial membranes.

31. Function: Function: 1-It is important in exchanging nutrients to and 1-It is important in exchanging nutrients to and from blood vessels. from blood vessels. 2-It binds structures together. 2-It binds structures together. 3-It limits the spread of localized infection. 3-It limits the spread of localized infection.

32. Loose Connective Tissue (Areolar)

33. Mucoid C.T (Wharton’s Jelly): Present mainly in the embryo. Formed of: Mucoid cells = U.M.C. or fibroblast joined by their processor. Mucoid cells = U.M.C. or fibroblast joined by their processor. Matrix: jelly like rich in mucin thin collagenfibres. Sites: In embryo: umbilical cord. In adult: Vitreous humour of eye. In adult: Vitreous humour of eye. Pulp of growing teeth. Pulp of growing teeth.

34. Dense collagen C.T.: - Either regular or irregular. I-The regular dense collagen C.T is characterized by close packing of fibres is found in tendons, aponeuroses, ligaments and cornea of the eye. II-The irregular dense collagen C.T is found in dermis, capsules of some organs, perichondrium and sclera of the eye. is found in dermis, capsules of some organs, perichondrium and sclera of the eye.

35. Dense Regular Connective Tissue

37. Yellow elastic C.T: Formed of condensed elastic fibres separated by fibroblast. Function: stretchable. Sites: Aorta & large arteries. Ranched tree. Ranched tree. Vocal cords. Vocal cords. Ligamentum nuchae (neck). Ligamentum nuchae (neck). Ligamentum flavum (between vertebrae). Ligamentum flavum (between vertebrae).

38. Loose Connective Tissue (Areolar)

39. Reticular C.T. -It is formed of reticular cells and fibres. The cells are stellate in shape with processes. -This tissue stains brownish black with silver -This tissue stains brownish black with silver - The main sites -Lymphoid tissues -Lymphoid tissues -Bone marrow -Bone marrow -Stroma of body organs -Stroma of body organs

40. Adipose C.T. -It is formed of lobes and lobules of fat cells separated by loose C.T. -It is formed of lobes and lobules of fat cells separated by loose C.T. -It is richly supplied with blood vessels. -It is richly supplied with blood vessels. -According to the vascularity and function, it is -According to the vascularity and function, it is divided into white and brown adipose C.T. divided into white and brown adipose C.T. The white type (Unilocular)is distributed in : * Adults subcutaneous tissue and yellow bone marrow. * Adults subcutaneous tissue and yellow bone marrow. - The brown type (Multilocular) is present : - The brown type (Multilocular) is present : * Foetus and newborn infants. * Foetus and newborn infants.

41. Adipose (Fat)