COMPONENTS ENDOTHELIAL CELLS PERICYTES PLASMA CELLS FIBROBLAST MAST CELLS ADIPOCYTES AND ADIPOSE TISSUE FIBER COMPONENTS GROUND SUBSTANCE BASEMENT MEMBRANE

2. CONTENTS
 INTRODUCTION
 COMPONENTS
 ENDOTHELIAL CELLS
 PERICYTES
 PLASMA CELLS
 FIBROBLAST
 MAST CELLS
 ADIPOCYTES AND ADIPOSE TISSUE
 FIBER COMPONENTS
 GROUND SUBSTANCE
 BASEMENT MEMBRANE
 CONCLUSION
 REFERENCES

3. What is a connective tissue?
Tissue
1. Fills the interstices between more specialized elements
2. Serves to hold them together
3. Support (supporting tissue)
Google image

4. *Mesenchyme
*Arise from mesoderm
*Widely spaced, pale staining stellate cells with long
interconnecting cytoplasmic processes
Google image

5. CLASSIFICATION
LOOSE/IRREGULAR DENSE/REGULAR SPECIALIZED
E.g.:
Reticular layer of
dermis
Fibrous capsule &
septa of glands &
organs
E.g.:
Tendons
Aponeuroses
Ligaments
Cartilage
E.g.:
Adipose tissue
Blood cells &
Blood forming
organs
Bone

7. *M
COMPONENTS
CELLS
EXTRACELLULAR
MATERIAL
GROUND
SUBSTANCE
Amorphous
intercellular non
fibrous
components
FIBRES
• Collagen
• Elastin
• reticulin
 ENDOTHELIAL
CELLS
 FIBROBLAST
 ADIPOCYTES
 MACROPHAGES
 PLASMA CELLS
 MAST CELLS

8. DEVELOPMENT
Arise from embryonic
mesenchymal cells
Line the entire circulatory
system constituting a simple
squamous epithelium-
endothelium
50µm long and 15µm wide
Google image

9. LIGHT MICROSCOPIC VIEW
Google image

10. ELECTRON MICROSCOPY
 Endocytic pits & vesicles
 Contractile filaments
 Few mitochondria
 Less rER and sER

12. FUNCTIONS OF ENDOTHELIAL CELLS
 Maintainence of the lining layer of the circulatory system
Facilitates exchange of substances across the capillary walls
Produce type III collagen and proteoglycans

13. (Gr. peri, around)
*Pale staining connective tissue
cells with long, slender
cytoplasmic process that lie
immediately external to the
endothelium
*Insinuated into the basement
memberane
*Mesenchymal potentiality
Google image

14. Google image

15. FUNCTIONS
Regulation of blood flow
Inflammation
Immune function
Wound healing
Vascular development/ angiogenesis

16. HEMANGIOPERICYTOMA
tumor derived from pericytes
*numerous vascular channels showing
plump endothelial nuclei and indistinct
cytoplasm
*Staghorn appearance
Pericytes in Health and Disease;Prashant B Munde, Shubhangi P Khandekar, Alka
M Dive, Neha R Upadhyaya
Hemangiopericytoma of gingiva-A Case Report; Dr gayathri Ramesh

17. FIBROBLAST
(L. fibra; blastos, germ)
Produces fibers and
amorphous ground substance
Google image

18. LIGHT MICROSCOPIC VIEW
ACTIVE
o Wide cytoplasmic processes or
appear spindle shaped
o basophilic cytoplasm
o Prominent nucleoli
INACTIVE
o Fibrocytes
o Flattened ovoid nucleus
o Condensed chromatin
o Less basophilic cytoplasm
Google image

19. MACROPHAGE
Histiocytes
Development- mesenchyme
Precursor cell- monocytes
12µm diameter
 engulf particulate matter and
submit it to lysosomal hydrolysis
Round to oval or angular
shape
Dark staining nucleus
Eccentrically placed
Indented oval or kidney
bean shaped
Google image

20. ANTIBODY MOLECULES CAN FACILITATE PHAGOCYTOSIS
PREFORMED ANTIBODIES
posses cell surface receptors for the Fc end of the antibody
molecule
FUNCTIONS
 Elimination of microorganisms, the cellular debris, exogenous material,
worn out blood cells in the spleen
 Fuse and form multinucleated giant cells
 Represents the cellular source of – complementary proteins,
hematopoietic growth regulators
Antigen stimulated
regulatory T-
lymphocytes
Migration
inhibitory factor
macrophages

21. PLASMA CELLS
DEVELOPMENT- mesenchyme derived B lymphocytes
Coons (1955)- antibody is produced from plasma cells
They contain RUSSEL BODIES (2µm-3µm) in diameter
Google image-
FUNCTIONS
Secretion of
antibodies

22. LM
Rounded in outline
15µm in diameter
intense cytoplasmic basophilia
NUCLEUS:
Eccentrically placed, Spherical to
ovoid,Clumps of peripheral
condensed chromatin,Large
nucleolus
Google image- plasma cell leukemia

23. PLASMA CELL DYSCRIASIS
1.PLASMACYTOMA
Google image

24. MULTIPLE MYELOMA

25. MAST CELLS
DEVELOPMENT : HEMATOPOIETIC STEM CELL

MAST CELLS
LM
 Large rounded or ovoid
cells
Contains numerous
spherical, membrane-
bounded secretory
granules
Less prominent in H & E
staining
EM
 Irregular outline,
 Numerous mitochondria,
 Prominent rER, golgi
apparatus
Histamine
Heparin
serotonin

26. EM LM
Google image

27. MEDIATORS
1.Histamine
2.ECF-A
3.NCF
4.Lysosomal hydrolases
5.SRSA
6.PAF
7.Prostaglandins

28. HISTAMINES
Derived from histidine
contract visceral smooth muscles and cardiac smooth muscle
Relax all the other muscles
MAST CELL DEGRANULATION
the cell membrane of mast cell is provided with Fc receptors
Affinity for IgE

29. DEGRANULATION OF MAST CELLS
Google image

30. MAST CELL ACTIVATION DISEASES
SYSTEMIC MASTOCYTOSIS
Google image

31. ADIPOCYTES AND ADIPOSE TISSUE
DEVELOPMENT- pericapillary mesenchymal cells
 Signet ring appearance
 Chicken wire appearance
 70µm-120µm diameter
 Rim of cytoplasm is 1µm-
2µm
 Prominent mitochondria
Google image

32. LIPOMA

33. INTERCELLULAR COMPONENTS OF CONNECTIVE
TISSUE
INTERCELLULAR FIBERS
COLLAGEN---STRONG FIBERS MADE OF PROTEINS
ELASTIN----ELONGATE PASSIVELY WHEN STRETCHED
RETICULIN-AMORPHOUS INTERCELLULAR COMPONENTS
PROTEOGLYCANS & GLYCO PROTEINS---FILL
INTERSTITIAL GAPS BETWEEN THE COMPONENTS OF
CONNECTIVE TISSUE

34. COLLAGEN
Main fibre type
Tropocollagen – alpha chains (3 polypeptide chains)
300 nm long and 1.5nm diameter
Triple helix structure
2 UNIQUE AMINOACIDS- proline & glycine
Hydroxyproline- hydrogen bonds
Hydroxylysine - collagen crosslinking
attachment of short carbohydrate chains

35. P
R
O
C
O
L
L
A
G
E
N
S
E
C
R
E
T
I
O
N

37. MASSON’S TRICHROME STAININING OF COLLAGEN
VAN GIESON STAINING
Google image

38. AXIAL PERIODICITY
Repeating pattern of light and dark bands
64nm periodicity reflects the unique pattern of incorporation of
collagen molecule into the fibril

39. COLLAGEN DEGRADATION
Collagenases- fibroblasts, macrophages and neutrophils at neutral pH
Lysosomal elastase- neutrophils and macrophages
Lysosomal cathepsin (B & N)- at low pH

40. COLLAGEN DISORDERS
1.SCURVY
2.SYSTEMIC SCLEROSIS 3.SYSTEMIC LUPUS
ERYTHEMATOSIS
Google image

41. ORAL SUBMUCOUS FIBROSIS
HISTOPATHOLOGY (H & E 100x)
REF-Oral submucous fibrosis and its
dermatological relation

42. 2.EHLER DANLOS SYNDROME
 First decribed by Van Meekeran in 1682
 Interferences with conversion of
procollagen to collagen
3. OSTEOGENESIS IMPERFECTA
 Decrease in collagen
synthesis or defective
collagen synthesis.
4.STICKLER SYNDROME
Gunnar B stickler
COLI A1,
COLI A2
COL1A1
on ch 17,
COL1A2
on ch 7
COL12A1,
COL11A1,C
OLI1A2
Google image

43. 5.ALPORT SYNDROME
Inherited disorder of basement
membrane particulary type IV collagen
Mutations in gene located in X
chomosome
6.MARFAN SYNDROME
Autosomal dominant
mutations in the genes
encoding fibrillin
COL4A4
COL4A3
COL4A5
FNB ch
15q15
23.1
Google image

44. ELASTIC FIBERS
0.2- 1.5µm in diameter
Less wavy, branched,
irregular
Stained by resorcin fuchsin,
aldehyde fuchsin, van gieson
staining
tropoelastin
Desmosine
isodesmosine
ELASTIN

45. Google image

46. RETICULAR FIBERS (L.rete,net)
Thin 0.5 and 2 μm diameter
Not visible in H & E stains but can be easily stained black by
impregnation with silver salts
Argyrophilic fibers – affinity to silver salts
Fine, delicate & branch extensively
Transverse section of
smooth muscle
impregnated with
silver to stain the
reticular fibers
Google image

47. Coated with glycoprotein and polysaccharide-containing
proteoglycan
FUNCTIONS:
 Provide intimate support for capillaries, nerve fibers,
muscle fibers
 closely associated with basement membrane
 fine supporting elements for the parenchymatous cells of
major glands such as liver & blood-forming cells in
myeloid & lymphatic tissue
TISSUE DISTRIBUTION:
Smooth muscle, endoneurium,
hematopoietic organs, around
parenchymal organs

48. GROUND SUBSTANCE
Complex and hydrated semisolid gel
Acid mucopolysaccharides, glycosaminoglycans
Glycosaminoglycans= disaccharides= uronic acid+hexose
sugar
2 types- sulfated and sulfate free

49. HYALURONIC ACID
sulfated
Long, irregularly folded
400nm in diameter
Interstices are filled with tissue fluid
disaccharide=
N-acetyl glucosamine
+
glucoronic acid

50. S NO GLYCOSAMINOGLYCANS REPEATING DISACCHARIDE
UNITS
1
HEPARAN SULFATE N- acetylglucosamine and
glucoronic or iduronic acid
2
CHONDROITIN-4-SULFATE
CHONDROITIN-6-SULFATE
N-acetylgalactosamine and
glucoronic acid
3
DERMATAN SULFATE N- acetylgalactosamine and
glucoronic acid or iduronic acid
4
KERATAN SULFATE N- acetylglucosamine and
galactose

51. 4 main gags-
1. DERMATAN SULFATE- skin, tendon aorta
2. CHONDROITIN SULFATE — hyaline cartilage, bone,
cornea,skin, aorta
3. KERATAN SULFATE — cornea
4. HEPARAN SULFATE — aorta, lung, liver, basal, basal
laminae.

52. GAGS
PROTEOGLYCANS
AND
GLYCOPROTEINS ???

53. STAINING?
GAGS AND
PROTEOGLYCANS
METACHROMATIC
STAINING,
COLLOIDAL IRON,
PAS NEGATIVE
GLYCOPROTEINS
PAS POSITIVE

54. FLUID COMPONENT OF THE GROUND SUBSTANCE
TISSUE FLUID AND LYMPH
OEDEMA
Google image

55. BASEMENT MEMBRANE
Immediately beneath the basal surface of epithelial
membranes
PAS positive
In electron micrograph- electron dense layer
100nm thick
Basement membrane/ basal lamina

56. LM OF TRANSITIONAL
EPITHELIUM
ELECTRON MICROSCOPIC
VIEW
Google image
Google image

57. *LAMINA DENSA- electron dense layer (20 -300 nm)
*LAMINA RARA- electron lucent layer
Collagen?
TYPE IV, TYPE III (fibroreticularis)
LAMINA RARA
INTERNA
LAMINA RARA
EXTERNA
LAMINA
LUCIDA
LAMINA
FIBRORETICULARIS

58. Google image

59. *Anastomosing cords possess an axial core filament made of TYPE
IV collagen surrounded by LAMININ and FIBRONECTIN ,
ENTACTIN, HEPARIN SULPHATE
FIBRONECTIN
 Attaching basement
membrane to the
reticular fibers
 cellular adhesion to
the basement
membrane
LAMININ
 Attach cells to the
basement membrane

60. FUNCTIONS
Bond cells to underlying connective tissue
Provides support
Freely permeable to substances of low molecular weight
and impedes the substances of high molecular weight
Act as a substrate capable of directing cell growth and
migration during morphogenesis , regeneration and
repair

61. REFERENCES
1.Ham’s histology
2.’Collagen in health in disease’;Simarpreet V Sandhu, Shruthi Gupta, Himanta
Bansal,, Kartesh Singla; Journal Of Orofacial Research; July-September
2012;2(3):153-159
3. ‘Pericytes in Health and Disease’; Prashant B Munde, Shubhangi P
Khandekar, Alka M Dive, Neha R Upadhyaya ;International Journal of Oral
and Maxillofacial Pathology ; November 2014;5(1):02-07