Histology of Connective Tissue.pptx

Connective tissue is the tissue that connects or separates, and supports all the other types of tissues in the body. Like all tissue types, it consists of cells surrounded by a compartment of fluid called the extracellular matrix (ECM). However connective tissue differs from other types in that its cells are loosely, rather than tightly, packed within the ECM.

1. HISTOLOGY OF CONNECTIVE TISSUE Dr Mathew Joseph MBBS,MD(AIIMS),BCC(Palliative Medicine) Assistant Professor Department of Anatomy Amala Institute of Medical Sciences, Thrissur

2. CONNECTIVE TISSUE O ne of the 4 basic tissues which gives structural and metabolic support to the organ and other tissue s of the body. It connects other tissues.

3. Functions Support Structural & Mechanical Packing Fills spaces, Shape to the organ Storage Adipose tissue: energy Loose areolar CT: water & Electrolytes Transport Medium for Nutrients & Metabolic wastes Repair Fibroblasts:matrix and fibres Defense Cells: Phagocytosis o r Antibodies

4. CONNECTIVE TISSUE GENERAL FEATURES 1. Cells 2. Matrix - Fibers - Ground substance

5. CONNECTIVE TISSUE Major constituent- Extracellular Matrix Strength

6. Cells of Connective Tissue A. Fixed cells (intrinsic cells ) 1. Fibroblast s & Fibrocytes 2. Mesenchymal cells (ASC) 3. Adipocyte s 4. Fixed macrophages 5. Mast cells 6. Pigment cells B. Free cells (extrinsic cells/Wandering Cells) 1 . Free m acrophage s 2 . M onocytes 3 . Plasma cells 4 . Leu k ocytes

7. Function Fixed Cells : Production & Maint a nance of Extracellular ma trix. Free Cells : Tissue reaction to injury or invasion of micro o rganisms.

8. Fibroblast Most numerous cell type (PCTC). Mesenchymal origin Fusiform with slender cytoplasmic process Cental l arge oval nucleus Old and inactive - Fi brocyte s Contractile c ells - M yofibroblast Wound repair Responsible for fiber production Reticular tissue

9. Fibroblast

10. Adipocytes Lipocytes - L ipid storing Spherical - Peripheral rim of cytoplasm - Eccenteric nucleus - Central large lipid droplet. Appears as empty space ** Incapable of division Aggregate in adipose tissue with reticular fibre . Sudan III, Sudan Black

11. Mesenchymal cells Undifferentiated cells Stellate in shape Cytoplasmic process Pluripot ent cell s Embryonic connective tissue

12. Macrophages (Histiocytes) Clasmatocytes - Monocytes - Kupffer cells - Microglia - Alveolar phagocytes - Langerhans cells - Hofbauer cells . Mononuclear phagocytic system (MPS) Phagocytose - Organic and Inorganic Free & Fixed type s Fixed - Fibers - Fibroblasts - F ilopodia proces s Free - Rounded - Nomadic - No Filopodia Dark indented eccentric nucleus - Kidney shaped Cytoplasm - Lysosomes (EM) G iant cell s - Barrier - (MGC)

13. Plasma cells Antibody producing - derived from B-lymphocyes. Oval - basophilic cytoplasm - RER Eccentric nucleus - He terochromatin as cartwheel appearance. Produces I mmunoglobulin Antibod ies - Discharged locally - Circulation - Russell bod ies. Present in respiratory tract and gastrointestinal tract 10-30 days

14. Mast cell Mastocytes - Histaminocytes - Round or Fusiform - Filopodia Round nucleus - Look like basophil, so called as connective tissue basophil Metachromatic granules in cytoplasm Mucopolysaccharide g ranules have Histamine or Heparin Blood vessels-allergic reactions Connective tissue mast cell – H eparin granule, present in skin. Mucosal mast cell – small - present in lamina propria of git and respiratory tract Brain - Spinal cord

15. Leucocytes . Granulocytes -Neutrophils, Esinophils, Basophiles . Agranulocytes Lymphocytes -T,B,NK Monocytes

16. Leucocytes

17. Fibers in Connective Tissue Strength to CT Collagen - Elastic - Reticular

18. Collagen Fibre White colour when fresh Do not branch - wavy - B undle s Collagen protein forms Fibres Fibres composed of fibril made of microfibrils Micro fibrils made up tropocollagen -striations Synthesized by fibroblast

19. Collagen Tropocollagen is synthesized by fibroblasts and released into extracellular space where they get polymerized to form collagen fibrils Collagen on boiling gives gelatin More than 25 types are present Collagen is also synthesized by C hondroblasts - Cartilages Osteoblasts : in bone Smooth Muscle : in blood vessels Odontoblasts : in the tooth

20. Collagen Types Type1 - bones ,tendons, dermis etc Type2 -cartilage , IVD, VHE Type3 -reticular fibres , BV, Skin Type4 -basement membrane Type5 - with T1

21. Synthesis Amino acids Procollagen Three chains Tropocollagen Collagen

22. Elastic fibre Yellow in color when fresh Composed of elastin protein Singly present Branched and anastomose forming a network Can be stretched (one and a half times) Synthesized by fibroblast and smooth muscle cells in blood vessels Found in ligamentum flava , ligamentum nuchae , large arteries Elastase

23. Reticular fibre Structurally similar to collagen fibres Are very thin Immature collagen fibre Actively branch to form delicate network therefore named Reticular Form supportive framework of lymphoid tissue - S, LN - LIV KID Stained black by silver salts ( argyrophillic ) Composed of Collagen Type III

24. Ground Substance Transparent & Homogeneous - Fills spaces between cells and fibres . Fibroblasts - Chondrocytes - Osteocytes - Smooth muscles Acts as a moleculer sieve facilitating diffusion between blood and tissues. Composition Mucopolysaccharides - Proteoglycans - Glycosaminoglycans Structural Glycoproteins Water & Electrolytes

25. Mucopolysaccharides ( Glycosaminoglycans ): Consistency & viscocity of GS, serves as a physical barrier in spreading infection . Examples: Hyaluronic Acid & Heparan Sulphate . Structural Glycoproteins : Adhesion of cells to the neighbouring cells. Examples: Fibronectin (Dermis), Chondronectin (in Cartilage) & Laminin (in basement membrane) Water & Electrolytes : Maintenance of Fluid balance.

26. Ground substance Polysacchrides - hexurate or galectose Carbohydrate protein complex ( proteoglycanes )- 1- mucopolysacchride ( glucosaminoglycanes ) NonSulphates -chondroitin and hyluronic acid Sulphates - chondotinesulphate , heparitine sulphate , keratohyline 2- glycoprotienes - fibronectine (dermis), chondronectine (cartilage), laminin ( b.m ) water & minerals

27. Classification of Connective Tissues 1.Ordinary connective tissue- Loose connective tissue -Dense connective tissue Regular Irregular 2. C onnective tissue with special properties Adipose tissue Mucoid tissue Reticular tissue Pigmented tissue 3. S keletal connective tissue -Bone -Cartilage 4. Lymphoid and heamopoietc connective tissue

28. Classification of Connective Tissues Loose areolar connective tissue - subperitoneal tissue, endomysium , lamina propria Dense collagenous C T Regular- tendon, ligament, aponeurosis Irregular-dermis of skin Connective T with special propert ies Elastic- Ligamentum nuchae Mucoid / Embryonic tissue- Wharton’s jelly Reticular Tissue- Stroma of lymphoid organ

29. Loose connective tissue

30. Dense Regular Connective Tissue

31. Dense Regular Connective Tissue

32. Dense Irregular Connective Tissue

33. Dense Irregular Connective Tissue

34. Dense Irregular Connective Tissue

35. Dense Irregular Connective Tissue

36. Irregular Elastic Connective Tissue

37. Irregular Elastic Connective Tissue

38. Regular Elastic Connective Tissue

39. Regular Elastic Connective Tissue

40. Reticular Connective Tissue

41. Adipose Connective Tissue

42. Irregular Adipose Connective Tissue

43. Mucoid Tissue

44. Self Assessment Plasma Cells are derived from : 1. Monocytes 2. Basophils 3. T lymphocytes 4. B Lymphocytes

45. Large number of elastic fibres are present in 1. Tendon 2. Ligamentum Nuchae 3. Basement Membrane 4. Aponeurosis

46. The fat cells of Multilocular adipose tissue (Brown fat) is characterized by the presence of 1.Spherical central nucleus and many lipid droplets. 2.Flat peripheral nucleus and single lipid drop 3. Flat central nucleus and single lipid droplet 4. Thin rim of cytoplasm

47. Thank You