Connective tissue is one of the four primary tissue types, characterized by its abundance and diverse functions, which include supporting and connecting tissues, as well as transporting substances. It consists of an extracellular matrix composed of fibers (collagen, elastic, reticular), ground substance, and various cell types. Connective tissue can be categorized into different classes, including loose, dense, specialized, and embryonic connective tissues, each with unique structures and roles in the body.

2. Connective tissue is one of the four tissue
types found throughout the body.
Connective tissue is the most abundant
and widely distributed tissue in the body.

3. Connective tissue develop from mesoderm
during embryonic development.
While some connective tissues are specialized
( bone , blood), all organs have some amount
of connective tissue in them which hold their
parenchyma together.

4. Major constituent is extracellular matrix,
composed of fibres, ground substance &
tissue fluid.
Embedded within the extracellular matrix
are the connective tissue cells.

5. Structurally, connective tissue can be
divided into 3 classes: cells, fibres &
ground substance.

6. More matrix than cells
Derived from mesoderm in embryo –
mesenchyme and mucous connective
tissue.
Vascular .

7. Can replicate (healing and repair).
Is not present on free surfaces or body
cavities

8. Enclosing and separating organs
Connecting tissues to one another
(ligaments and tendons).
Supporting and moving ( Joints and
cartilage)

9. Storing (adipose tissue and bones)
Cushioning and insulating (adipose
tissues).
Transport and protection (blood)
Protection

10. Connective tissues differ widely but still
made up of three fundamental components
 Cells
 Protein fibers
 Ground substance( amorphous gelatinous
material)

11. It actually consists of large molecules
called glycosoaminoglycans (GAGs)
(unbranched polysaccharide chains)which
link together to form even larger
molecules called proteoglycans

12. Protein fibers and ground substance are
collectively called as extracellular matrix
The composition and structure of
extracellular matrix determine function
and characteristic of connective tissue

13. Ground substance
• Medium through which solutes diffuse
between blood capillaries and cells.

14. • Components:
Interstitial fluid
Adhesion proteins (“glue”)
Proteoglycans

15. Three types of fibers
• Collagen (white fibers)
Strongest and most abundant type
Provides high tensile strength

16. It is a protein composed primarily of the
amino acids glycine & proline, and it also
contains sugar groups.

17. • Elastic
Networks of long, thin, elastin fibers
that allow for stretch.
• Reticular
 Short, fine, highly branched

18. Classification is based on the composition
and organization of cellular and
extracellular components and on special
functions.

19. CLASSIFICATION
CONNECTIVE TISSUE
PROPER
SPECIALIZED
CONNECTIVE TISSUES
EMBRYONIC
CONNECTIVE TISSUE

20. SPECIALISED CONNECTIVE
TISSUE
ADIPOSE CONNECTIVE
TISSUE
RETICULAR CONNECTIVE
TISSUE
ELASTIC CONNECTIVE
TISSUE

21. EMBRYONAL
CONNECTIVE TISSUE
MESENCHYMAL
CONNECTIVE TISSUE
MUCUOS
CONNECTIVE TISSUE

22. CONNECTIVE TISSUE
PROPER
LOOSE
CONNECTIVE
TISSUE
DENSE CONNECTIVE TISSUE

23. Dense connective
tissue
Dense regular
Dense irregular
Elastic
Loose connective
tissue
Areolar
Adipose
Reticular

24. Areolar connective tissue is highly
variable in appearance and the most
widespread of all the connective tissue
types specialized connective tissue in the
body .

25. consists of
fibers (collagen, elastic, reticular) arranged
randomly .
several kinds of cells (fibroblasts,
macrophages, plasma cells, adipocytes,
mast cells, and a few white blood cells)

26. semifluid ground substance (hyaluronic
acid, chondroitin sulfate, dermatan
sulfate, and keratan sulfate).
Its functions are connects ,strength,
elasticity, support.

27. Present everywhere in body including
subcutaneous layer deep to skin,
superficial region of dermis of skin,
mucous membranes, around blood
vessels, nerves, and body organs

29. Made up of adipocytes that are
specialized for storage of triglycerides
(fats) as a large, centrally located droplet.

30. Function: Reduces heat loss through skin,
serves as an energy reserve, supports and
protects organs in newborns.

31. Present throughout the body;
abdominopelvic cavity, around kidney,
subcutaneous tissue.

33. Reticular connective tissue contains a
meshwork of reticular fibers, on which
fibroblast and leukocytes are suspended.

34. Has very little ground substance.
Mainly present in hematopoietic system;
spleen, lymph nodes, bone marrow

35. Functions: Forms stroma of organs, filters
and removes worn-out blood cells in
spleen and microbes in lymph nodes

37. Dense connective tissue consists of
densely packed fibers with relatively
little space between the fibers.
Has proportionately high protein fiber
than ground substance.

38. Also called collagenous connective tissue
because of abundance of collagen fibers.

39. Further divided into three categories.
 Dense regular connective tissue
 Dense irregular connective tissue
 Elastic connective tissue.

40. Figure 4.8d
Connective tissue proper: dense connective tissue, dense regular
Description: Primarily parallel
collagen fibers; a few elastic fibers;
major cell type is the fibroblast.
Function: Attaches muscles to
bones or to muscles; attaches bones
to bones
Location: Tendons, most
ligaments
Photomicrograph: Dense regular connective
tissue from a tendon (500x).
Shoulder
joint
Ligament
Tendon
Collagen
fibers
Nuclei of
fibroblasts

41. Figure 4.8e
Connective tissue proper: dense connective tissue, dense
irregular
Description: Primarily
irregularly arranged collagen
fibers; some elastic fibers;
major cell type is the fibroblast.
Function: Able to withstand
tension in many
directions; provides structural
strength.
Location: Fibrous capsules of
organs and of joints; dermis of
the skin; submucosa of
digestive tract.
Photomicrograph: Dense irregular
connective tissue from the dermis of the
skin (400x).
Collagen
fibers
Nuclei of
fibroblasts
Fibrous
joint
capsule

42. Figure 4.8f
Connective tissue proper: dense connective tissue,
elastic
Description: Dense regular containing a
high proportion of elastic fibers.
Function: Allows flexibility
Location: Walls of large arteries;
walls of the bronchial tubes.
Elastic fibers
Aorta
Heart
Photomicrograph: Elastic connective tissue in
the wall of the aorta (250x).

43. Three types of cartilage:
• Hyaline cartilage
• Elastic cartilage
• Fibro cartilage

44. Figure 4.8g
Cartilage: hyaline
Description: Amorphous but firm matrix; collagen fibers form
network; chondroblasts produce the matrix and when mature
(chondrocytes)
Function: Supports and
resists compressive stress.
Location: Forms most of the
embryonic skeleton; covers the ends
of long bones in joint cavities; forms
cartilages of the nose, trachea, and larynx.
Photomicrograph: Hyaline cartilage from the
trachea (750x).
Costal
cartilages
Chondrocyte
in lacuna
Matrix

45. Figure 4.8h
Cartilage: elastic
Description: Similar to hyaline
cartilage, but more elastic fibers
in matrix.
Function: Maintains the shape
of a structure while allowing
great flexibility.
Location: Supports the external
ear
Chondrocyte
in lacuna
Matrix

46. Figure 4.8i
Cartilage: fibrocartilage
Description: Matrix similar to
but less firm than that in hyaline
cartilage; thick collagen fibers
predominate.
Function: Tensile strength
with the ability to absorb
compressive shock.
Location: Intervertebral discs;
Photomicrograph: Fibrocartilage of an
intervertebral disc (125x). Special staining
produced the blue color seen.
Intervertebral
discs
Chondrocytes
in lacunae
Collagen
fiber

47. Figure 4.8j
Others: bone (osseous tissue)
Description: Hard, calcified
matrix containing many collagen
fibers; osteocytes lie in lacunae.
Function: Bone supports
provides levers for the muscles
to act on; stores calcium and fat;
marrow inside bones is the site for
blood cell formation
Location: Bones
Photomicrograph: Cross-sectional view
of bone (125x).
Lacunae
Lamella
Central
canal

48. Figure 4.8k
Others: blood
Description: Red and white
blood cells in a fluid matrix
(plasma).
Function: Transport of respiratory
gases, nutrients, wastes, and other
substances.
Location: Contained within
blood vessels.
Neutrophil
Red blood
cells
Lymphocyte
Plasma

49. These are the most frequently
encountered of all the fibrous types of
intercellular substance, and are found in
large quantities in most sites in the body.

50. These are found in all types of connective
tissue and consist of protein collagen.
In the fresh state, e.g. in tendons, they
appear white, and hence also are termed
“white” fibers.

51. They may occur as individual fibers, as in
loose areolar tissues.
Or as large bundles of fibers clumped
together.
Within a bundle, fibers are held together
by a small amount of amorphous
substance (mucoprotein).

52.  Most abundant structural
component of CT
 Flexible and gives high tensile
strength (due to covalent bonds
between them)
 Locations
• Type I = in loose and dense CT,
bone, skin, tendons & ligaments
• Type II= cartilage (hyaline &
elastic), intervertebral disc
• Type III = forms reticular fibers,
prominent in loose connective
tissue, organs ( liver, kidney, lung
etc., ) fetal skin

53. Collagen types
 Type IV= basal lamina (basement
membrane)
 Type V and VI= produce in small
amount by wide range of cells.
 LM = wavy structure,

54. Type I collagen stains strongly with acid
dyes, due to the affinity of the cationic
groups of the proteins for the anionic
reactive groups of the acid dyes.

55. Collagen may be demonstrated more
selectively by compound solutions of acid
dyes (e.g. van Gieson) or by sequential
combinations of acid dyes

56. e.g. Masson’s trichrome, Lendrum’s
MSB, etc.) The different types of collagen
may be differentiated
immunohistochemically

57. This stain is mainly used to evaluate the
type and amount of extracellular material
like- collagen, fibrin, muscle and elastic
fiber.

58. Various technique includes:
Masson trichrome stain
Van gieson stain (Routine stain)
Mallory, Phosphotungstic or
phosphomolybdic acid stain


59. The general rule in trichrome staining is
that the less porous tissues are colored by
the smallest dye molecule;

60. whenever a dye of large molecular size is
able to penetrate, it will always do so at
the expense of the smaller molecule.

61. 1-Tissue permeability and dye molecular
size
Erythrocytes have density network(small
pores)
Muscles have medium pores
Collagens have large pores

62. 2-PH
3-Heat
4-Effect of fixation
5-Nuclear stains for trichrome stains

63. Purpose: Used to differentiate between
collagen and smooth muscle in tumors, and
the increase of collagen in diseases such as
liver cirrhosis.
Routine stain for liver and kidney biopsies

64. Principle: As the name implies, three
dyes 1-Harris Haematoxylin 2- acid
fuchsin 3- methyl blue are employed
selectively staining muscle, collagen
fibers, fibrin, and erythrocytes.

65.  Results:
Nuclei: blue ( Harris H)
Cytoplasm, muscle, erythrocytes: red( Acid
fuchsin)
Collagen: blue ( methyl blue)

67.  It is used to differentiate between collagen
and smooth muscle in tumour.
 To identify increased collagen deposition in
condition like cirrhosis, , benign prostatic
hyperplasia, membranoproliferative
glomerulonephritis etc.

69. Principle
 When using combined solution of picric acid
and acid fuchsin, the small molecules of picric
acid penetrate all the tissue rapidly, but are
only firmly retained in the close textured red
blood cells and muscle

70. The larger molecules of acid fuchsin
displaces picric acid molecule from
collagen fibres, which has larger pores
and allow larger molecules to enter

71. It is used for detection of collagen.
Result -- Nuclei : Blue / Black
 Collagen : Red
 ssCytoplasm, muscle, fibrin, RBCs :
Yellow

72. • Results:
• Collagen – deep red
• Muscle, RBCs –
yellow
• Nuclei – blue to black

73. These are the fine delicate fibers that are
found connected to the coarser and stronger
collagenous fibers (Type I fibers)
They provide the bulk of the supporting
framework of the more cellular organs (e.g.
spleen, liver, lymph nodes, etc.),

74. Reticulin fibers composed of protein
called reticulin.
Reticular fibers are very fine with a
diameter (0.2-0.5 micrometer's

75. Synthesized by:
Reticular cell in hemopoietic and
lymphatic tissues
Fibroblasts in other sites
Schwann cell in peripheral nerve
Fibers are not visible in H & E
preparations.

76. Demonstrated by means of impregnation with
silver salts and by PAS technique.
 Fibers are argyrophilic because of affinity
with silver salts, when impregnated with
silver they appear black (Gomori and Wilder
methods).

77. This affinity with silver salts and positive
PAS . is due to high content of hexoses 6-
12% as opposed to 1%in collagen.

78. 1. Diagnosis of liver cirrhosis.
2. To distinguish epithelial neoplasms from non-
epithelial neoplasms.
 Foci of carcinoma have reticulin around tumour
nest but not in between tumour cell, whereas in
most sarcomas and large cell lymphoma reticulin
separates single cells

79. To differentiate between in-situ and
invasive carcinoma

81. The elastic system fibers (i.e. oxytalan,
elaunin, and elastic fibers) have,
respectively, a fibrillar, amorphous, or
mixed structure

82. The elastic fibers may be found
throughout the body but are especially
associated with the respiratory,
circulatory, and integumentary
systems

83. Fibers are arranged mostly in parallel
though may join other bundle groups.
Fibers are elastic and may stretch at least
twice their length.

84. Oxytalan fibers may be distinguished
from mature elastic fibers by their failure
to stain with aldehyde fuchsin solutions,
unless they have been previously oxidized
by potassium permanganate

85. They have also been reported to remain
unstained following Verhöeff’s
hematoxylin, with or without prior
oxidation.

86. Elaunin fibers:Unlike oxytalan fibers,
elaunin fibers stain with orcein, aldehyde
fuchsin, and resorcin–fuchsin without
prior oxidation, but do not stain with
Verhöeff’shematoxylin

87. • Elastic fibres are composed of two components
MicrofibrilsElastin
•Occupies central portion
•Rich in proline and glycine
•Poor in hydroxyproline n
completely lacks
hydroxylysine
•Stains pale because it has
little affinity for heavy metal
salts
•A fibrillar glycoprotein
•Straight and thin
•Measuring12nm in
diameter

88. MARFAN SYNDROME:
In marfan syndrome, a complex connective
tissue disorder ,there is defect in fibril in
(a component of the micro fibril) protein.
Abnormal elastic tissue.

89. SCLERODERMA:
Skin diseases associated with accumulation
of elastin

90. This method is used for identifying elastic fiber
in tissue such as skin, aorta etc.
Result – Elastic fiber: Blue-black to black
- Nuclei: Blue to black
- Collagen: Red
- other tissue elements: Yellow

92. Basement membranes are found
throughout the body separating
connective tissues from epithelial,
endothelial or mesothelial cells, muscle
cells, fat cells, and nervous tissues

93. They support the epithelial cells of
mucosal surfaces, glands, and several
other structures, for example renal tubules
They also support the endothelial cells
lining blood vessels, capillaries

94. In H&E stained sections of most tissues,
basement membranes are difficult to
distinguish ,in the glomerulus hey are
more conspicuous, particularly in disorders
such as membranous nephropathy or
diabetes, where they can be markedly
thickened .

95. Basement membranes stain by PAS and
Periodic acid-methenamine silver
microwave method

97. ① fibroblast
---structure:
 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
 function: synthesize fibers and ground substance

98. fibrocyte: still state or inactive fibroblast
---structure:
spindle-shaped, small
N:small,dark stained
Acidophilic cytoplasm
---function: become into
fibroblast for repairing

99. fibrocyte
fibroblast
fibroblast fibrocyte

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

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

102. ③plasma cell
---structure:
 round or ovoid
 Nucleus with more spot-liked heterochromatin which
located eccentrically
 Basophilic cytoplasm
 function: synthesize and secrete immunoglobulin, Ig-
antibody

103. ④mast cell
---structure:
Round and large cell
Small dark-stained nucleus
Basophilic secreting granules

104. Basophilic secreting granules:
heparin: an anticoagulant
Histamine: cause cap. permeability↑, cap.
leakage to form edema and contraction of
SM
Eosinophil chemotactic factor
(chemotactic factor:
macrophage, leukocytes)

105. 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

106. ⑦leukocytes: neutrophil, acidophil and
lymphocyte, ect.
neutrophil acidophil lymphocyte