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
One of the 4 basic tissues which gives structural and
metabolic support to the organ and other tissues 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 or
Antibodies

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

5. CONNECTIVE TISSUE
Major constituent- Extracellular Matrix
Strength

7. Cells of Connective Tissue
A. Fixed cells (intrinsic cells)
1. Fibroblasts & Fibrocytes
2. Mesenchymal cells (ASC)
3. Adipocytes
4. Fixed macrophages
5. Mast cells
6. Pigment cells
B. Free cells (extrinsic
cells/Wandering Cells)
1. Free macrophages
2. Monocytes
3. Plasma cells
4. Leukocytes

8. Function
• Fixed Cells:
Production & Maintanance of Extracellular matrix.
• Free Cells:
Tissue reaction to injury or invasion of micro organisms.

9. Fibroblast
• Most numerous cell type (PCTC).
• Mesenchymal origin
• Fusiform with slender cytoplasmic process
• Cental large oval nucleus
• Old and inactive - Fibrocytes
• Contractile cells - Myofibroblast
• Wound repair
• Responsible for fiber production
• Reticular tissue

10. Fibroblast

11. Adipocytes
• Lipocytes - Lipid 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

13. Mesenchymal cells
• Undifferentiated cells
• Stellate in shape
• Cytoplasmic process
• Pluripotent cells
• Embryonic connective tissue

15. Macrophages (Histiocytes)
• Clasmatocytes - Monocytes - Kupffer cells - Microglia -
Alveolar phagocytes - Langerhans cells - Hofbauer cells.
• Mononuclear phagocytic system (MPS)
• Phagocytose - Organic and Inorganic
• Free & Fixed types
• Fixed - Fibers - Fibroblasts - Filopodia process
• Free - Rounded - Nomadic - No Filopodia
• Dark indented eccentric nucleus -
Kidney shaped
• Cytoplasm - Lysosomes (EM)
• Giant cells - Barrier - (MGC)

17. Plasma cells
• Antibody producing - derived from B-
lymphocyes.
• Oval - basophilic cytoplasm - RER
• Eccentric nucleus - Heterochromatin as
cartwheel appearance.
• Produces Immunoglobulin
• Antibodies - Discharged locally -
Circulation - Russell bodies.
• Present in respiratory tract and
gastrointestinal tract
• 10-30 days

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

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

23. Leucocytes

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

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

26. 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 Chondroblasts -
Cartilages
Osteoblasts : in bone
Smooth Muscle: in blood
vessels
Odontoblasts: in the tooth

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

28. Synthesis
• Amino acids
• Procollagen
• Three chains
• Tropocollagen
• Collagen

29. 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

30. 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

31. 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

32. • 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.

33. 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

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

35. 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 properties
Elastic-Ligamentum nuchae
Mucoid/ Embryonic tissue- Wharton’s jelly
Reticular Tissue- Stroma of lymphoid organ

39. Dense Regular Connective Tissue

40. Dense Regular Connective Tissue

41. Dense Irregular Connective Tissue

42. Dense Irregular Connective Tissue

43. Dense Irregular Connective Tissue

44. Dense Irregular Connective Tissue

45. Irregular Elastic Connective Tissue

46. Irregular Elastic Connective Tissue

47. Regular Elastic Connective Tissue

48. Regular Elastic Connective Tissue

49. Reticular Connective Tissue

50. Adipose Connective Tissue

51. Irregular Adipose Connective Tissue

53. Mucoid Tissue

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

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

57. • 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

58. Thank You