classification of connective tissue

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CLASSIFICATION OF CONNECTIVE
TISSUE
The connective tissues are classified into various types
depending on the following Four Factors.
1. Relative proportion of the various fibers present
2. Compactness and arrangement of fibers
3. Nature of ground substance (matrix)
4. Types of cells
On these ground the connective tissues are divided
into basic Groups
A. Embryonal Connective Tissue
B. Adult Connective Tissues
Connective Tissue
Adult
Embryonal
Proper
Cartilage
Bone
Mucous
Mesenchyme
Hyaline Fibro
Dense
Loose
Areolar
Elastic
Regularly
Arranged
Irregularly
Arranged
Reticular
Adipose
Embryonal Connective Tissue
Mesenchyme:
developmentally, the
connective tissue are
derived from mesoderm
(Mesenchyme) which
one of the three Primary
embryonic Layers
(others two are ectoderm
and Endoderm).
Immature connective
tissue of embryo derived
from the mesoderm is
called as Mesenchyme.
Embryonic Connective Tissue
--- Mesenchyme
• Consists of cells and ground substance with
reticular fibers
• Gives rise to all types of Connective Tissues
Embryonal Connective Tissue
Mucous Tissue: At the
later stages of
development of foetus
the mesnechmye
acquired abundant of
fibers, the increased
number of fibers in
mesenchyme now
called as Mucous,
which widely
distributed through out
the body of embryo.
Mucous Tissue
1-LOOSE CONNECTIVE TISSUE
Loose Areolar
connective Tissue:
This type is widely
distributed through out
the body. All three basic
components of
connective tissue (cells,
fibers and ground
substance) are best
represented in the loose
aerolar connective
tissue.
Green Lines - Collagen Fiber
Blue Circle - Mast Cells
Yellow arrows - Elastic Fiber
1- Loose Areolar connective Tissue:
The two most common cell
types, fibroblast and
histiocytes are present but
other varieties of cells also
present. Collagenous fibers
are more abundant but
elastic fibers are also
present.
Reticular fiber are few in
number.
Distributions:
 Subcutaneous Tissue
(Superficial & deep fascias)
Green Lines - Collagen Fiber
 Mesentery
Blue Circle - Mast Cells
 Omentum
Yellow arrows - Elastic Fiber
Connective tissue specialised
Adipose:
• Location – deep to skin: sides, buttocks, breasts; padding around
eyeballs and kidneys
• Function – insulation, mechanical support, stores energy.
Reticular:
• Location – spleen, lymph nodes, bone marrow
• Function – supporting framework for haemopoietic organs
•Mucoid: umbilical cord, incompressible
2- RETICULAR CONNECTIVE
TISSUE
This variety of loose
connective tissue
consists of reticular
cells and reticular
fibers. Reticular cells
have a stellate shape
and possess long
processes which pass
indifferent directions
to make contact with
neighbouring cells.
Reticular Tissue
2- RETICULAR CONNECTIVE
TISSUE
Distributions:
Forms the supporting
network of the liver,
spleen, bone marrow
and lymphoid organs.
Functions:
 Precursor for Fibroblast
 Producing Reticular
fibers
 Phagocytic Properties
3- ADIPOSE TISSUE
This variety of loose
connective consists of
entirely of fat cells,
organized into lobules
which are separated
from each other by
fibrous septa. Within a
lobule, the individual
fat cells are supported
by a mesh work of
delicate reticular fibers.
3- ADIPOSE TISSUE
Distributions:
Functions:
 Food reserve for the body
 Chief site for energy
storage
 Mechanical functions for
shock absorbing pad for
e.g. sole of foot.
 Temperature Regulation

By production heat as a
result of metabolism of fat.

By acting as the insulator
under the skin & preventing
the heat loss.
Types of Adipose Tissue
Two types of adipose
tissue are found in
animals: white adipose
tissue and brown
adipose tissue.
Brown Adipose CT
White Adipose CT
Brown Adipose Connective Tissue
Brown adipose tissue is
present in significant
amounts in human infants.
Its distributions is very
limited in the adult
In adult it is found in the
mediastinum, the
subcutaneous tissue
between the scapula, the
area around the kidney
and the area along the
aorta.
Brown Adipose Connective Tissue
Brown adipocytes are
small cells that contain
a centrally-placed
nucleus and large
numbers of
mitochondria.
Brown adipocytes are
multilocular cells, i.e.,
each cell contains
multiple small lipid
droplets.
Brown Adipose Connective Tissue
Brown adipose tissue has
a high metabolic rate
capable of generating
relatively high amounts of
heat, a process that is
physiologically important
to infants prior to the
maturation of their
thermoregulatory
mechanisms.
White Adipose Connective Tissue
White adipose tissue is
the principal type of
adipose tissue of the
adult human. The
tissue, which is
scattered about the
body, occupying
positions in skin and
around and within a
variety of other organs
White Adipose Connective Tissue
Distributions
It is the largest storage
reservoir of metabolic
fuel in the body, it serves
as a thermal insulator, in
the case of the skin, and
a protective cushion, in
the case of the adipose
that surrounds organs.
Its size and distribution
vary according to a
variety of factors,
including age and sex.
White Adipose Connective Tissue
Its important histologic
characteristics are:
The adipocytes are relatively
large, compared to brown
adipocytes, and are
dominated by the lipid
droplet.
White adipocytes are
unilocular cells, i.e., each cell
contains a single large lipid
droplet, a cytoplasmic
inclusion that contains
triacylglycerols and fatsoluble substances.
White Adipose Connective Tissue
The large lipid droplet appears
empty because the lipid is lost
during routine histological
preparation, and it displaces
the rest of the cell toward the
cells' periphery, flattening the
nucleus along the edge of the
cell, giving the cell a signet
ring appearance.
The tissue is well
vascularized, with
microvascular vessels found
in the sliver of loose
connective tissue found
between adjacent cells.
DENSE CONNECTIVE TISSUE
According to the
arrangement of its
component fibers, the
dense connective
tissue is subclassify
into two categories:
1. Regularly Arranged
connective Tissue
2. Irregularly Arranged
connective Tissue
REGULARLY ARRANGED
CONNECTIVE TISSUE
They are three types:a- Tendons: composed of
almost entirely of closely
packed collagen fibers.
A few fibroblasts are
present
b- Aponeuroses: have
same structure as the
tendon, but they are
broad and thin.
c- Ligaments: same as
tendons but more
sronger.
IRREGULARLY ARRANGED
CONNECTIVE TISSUE
This type of dense connective
tissue occurs in the form of
sheets. It mainly consists of
collagenous fibers, but elastic
and reticular fibers are also
present
Distributions:
Dermis of skin
Capsules of some organs (liver,
spleen, lymph nodes
Fibrous Sheaths of cartilage
(Perichondrium)
Fibrous Sheaths of bone
(periosteum)
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