Its about the definition, types, classification and function of connective tissue

1. Connective tissue: characteristics,
functions and types

2. Connective tissues are the major supporting tissue of the body. It is composed of variety
of cells, fibre (non-living products of cell) and semi-solid matrix between cells.
Characteristics of connective tissue
Connective tissue ranges from
avascular to highly vascular.
Composition: Composed mainly of
nonliving extracellular matrix that
separates the cells of the tissue.
Location: It is present in between
different tissue and organs. It can be
found in and around the body organs.
skeletal tissue present in the form of
bone and cartilage, and fluid connective
tissue as blood and lymph are
connective tissue.

3. Function of connective tissue
It binds various tissue together like skin with the muscles and muscles with bones
It form inter cellular substance between cells of different types of tissue, so that help in friction less
movement of the body organ
It forms sheaths around the body organs and make a kind of packaging tissue
The areolar tissue protects the body against wound and infection
The adipose tissue stores fats and insulates the body against heat loss
The supportive tissue forms shape and the frame work of the body
The haemopoitic tissue produce blood
The lymphatic tissue helps in body immunity

4. Types of connective tissue
A. Proper connective
tissue types
1. Loose connective tissue
Areolar connective tissue
Adipose connective tissue
Reticular tissue
II. Dense (fibrous) connective tissue
White fibrous tissue ( tendon and
sheath)
Yellow elastic tissue (Ligament)
B. Supporting connective tissue types
I. Cartilage
Hyline cartilage
Elastic cartilage
Fibrous cartilage
II. Bone
Spongy bone
compact bone
C. Fluid or liquid
connective tissue types
I. Blood
II. lymph

5. Areolar Connective tissue
1) They forms a loose network in
intracellular
material .
2) It consists of collagen, elastic
fibers, reticular
fibers and several kinds of cells.
Location: Below the skin, fill
space between muscles,
supports blood vessels and
nerves in alimentary canal.
Functions: It gives strength,
elasticity and support to tissue.
1. Loose connective tissue
A. Proper connective tissue types

6. It consists of adipocytes
which stores fat.
Location: It is present in
subcutaneous layer deep
in the skin, around the
heart and kidneys
Functions :
• Prevents heat loose from
body.
• Act as reservoir of
energy.
• It give shape to the limbs
and body.
• It protects underlying
organ from injury.
Adipose Connective tissue
1. Loose connective tissue

7. 1. Loose connective tissue
It contains reticular fibers and
reticular cells.
• Location: It is present in the
supporting framework of liver,
spleen, lymph nodes, red bone
marrow and it is also found
around blood vessels and
muscles.
• Functions: It binds together
smooth muscle tissue cells,
filters and removes microbes in
the lymph node.
Reticular Connective tissue

8. 1I. Dense connective tissue
It is of two types, Fibrous tissue and Elastic Tissue
Fibrous tissue
In this tissue, fibers are densely packed.
• The fiber content is higher.
• Cell content is lower as compared to loose connective tissue.
• It is of two types, Dense regular connective tissue and dense irregular connective tissue.
Dense Regular Connective Tissue
Bundles of collagen fibers are arranged in parallel
patterns to provide strength to tissue.
• Fibroblast are appear in rows between the
fibers.
• It is tough in nature.
Location: It forms tendons (attach muscle bone)
and ligaments(attach bone to bone).
Functions: It provides strong attachment to
structure.
Dense Irregular Connective Tissue
It contains collagen fibers which are irregular
arranged and a few fibroblasts are appear in
rows between the fibers.
Location: It present in dermis layer of skin,
membrane capsules around kidneys, liver, testes
and lymph node, heart valves.
Functions: It provides strength to different organs.

9. 1I. Dense connective tissue

10. Elastic Tissue
1I. Dense connective tissue
It consists of freely branching elastic
fibers.
• Fibroblast are present in space
between fibers.
• It is yellowish in colour.
Location: It is present in tissues , walls
of elastic arteries, trachea, bronchial
tubes and vocal
cords.
Functions: It allows stretching of
various organs.

11. B. Supporting connective tissue types
It consist of network of closely packed collagen fibers and elastic fibers.
The cells of mature cartilage called as chondrocytes.
I. Cartilage connective tissue
•It is bluish white in color.
•It consists of fine collagen fibers
and many chondrocytes.
Location: It is present at the end
of long bones, anterior ends of
ribs, nose and parts of larynx,
trachea, bronchi, bronchial tubes.
Function: It provides small
surface for movement at joints,
flexibility and support
Hyaline Cartilage Fibro Cartilage Elastic Cartilage
• It is strongest form of
cartilage.
• The chondrocytes are
scattered among the
bundle collagen fibers
within the extracellular
matrix.
Location: It is present in
inter-verteblar disc.
Functions: It covers and
protects bony structures of
body.
• The chondrocytes are
located within a threadlike
network of elastic fibers within
extracellular matrix.
Location: It is present in
pinna of ear and top of larynx.
Functions: It provides
strength and elasticity and
maintain the shape of certain
organs such as the external
ear.

12. I. Cartilage connective tissue
Hyaline Cartilage
Fibro Cartilage
Elastic Cartilage

13. II. Bone connective tissue
Compact
Osteon – basic unit of compact
bone
Lamellae – concentric circles of
matrix
Lacunae – spaces in the matrix
that house cells
Osteocytes – mature bone cells
Spongy
Trabeculae – columns of
bone with spaces filled
with red bone marrow
An electron
micrograph scan of
spongy bone in an
osteoporosis patient.
Osteoporosis occurs
when a body's blood
calcium level is low
and calcium from
bones is dissolved into
the blood to maintain a
proper balance
(2 types – compact and spongy)

14. C. Fluid or liquid connective tissue types
Connective Tissue with a liquid
matrix
Red Blood Cells (erythrocytes) –
transport oxygen
White Blood Cells – function in
immunity (Neutrophils, Eosinophils,
Basophils, T and B leukocytes,
natural killer cells and Monocytes)
Platelets (participate in blood
clotting)
I. Blood connective tissue

15. Information that identifies a few select features of
connective tissue
Nerve supply
Most connective tissues have a nerve supply (as does epithelial tissue).
Blood supply
There is a wide range of vascularity among connective tissues, although most are well
vascularized (unlike epithelial tissues, which are all avascular).
Structure
Connective tissue consists of scattered cells immersed in an intercellular material called the
matrix. The matrix consists of fibers and ground substance. The kinds and amounts of fiber
and ground substance determine the character of the matrix, which in turn defines the kind of
connective tissue.

16. Cell types
Fundamental cell types, characteristic of each kind of connective tissue, are responsible for producing the
matrix.
Immature forms of these cells (whose names end in blast) secrete the fibers and ground substance of the
matrix.
Cells that have matured, or differentiated (whose names often end in cyte), function mostly to maintain
the matrix:
Fibroblasts are common in both loose and dense
connective tissues.
Adipocytes, cells that contain molecules of fat,
occur in loose connective tissue, as does adipose
tissue.
Reticular cells resemble fibroblasts, but have long,
cellular processes (extensions). They occur in loose
connective tissue.
Chondroblasts and chondrocytes occur in
cartilage.
Osteoblasts and osteocytes occur in bone.
Hemocytoblasts occur in the bone marrow and
produce erythrocytes (red blood cells), leukocytes
(white blood cells), and platelets (formerly called
thrombocytes).
leukocytes migrate from the bone marrow to
connective tissues and provide various body defense
activities:
Macrophages engulf foreign and dead cells.
Mast cells secrete histamine, which stimulates
immune responses.
Plasma cells produce antibodies.

17. Fibers
Matrix fibers are proteins that provide support
for the connective tissue. There are three types:
Collagen fibers, made of the protein
collagen, are both tough and flexible.
Elastic fibers, made of the protein elastin,
are strong and stretchable.
Reticular fibers, made of thin collagen
fibers with a glycoprotein coating, branch
frequently to form a netlike (reticulate)
pattern.

18. Ground substance
Ground substance may be fluid, gel, or solid, and, except for blood, is secreted by the cells of the
connective tissue:
Cell adhesion proteins hold the connective tissue together.
Proteoglycans provide the firmness of the ground substance. Hyaluronic sulfate and
chondroitin sulfate are two examples.

19. Classification
There are five general categories of mature connective tissue:
Loose connective tissue has abundant cells among few or loosely arranged fibers and a sparse to
abundant gelatinous ground substance.
Dense connective tissue has few cells among a dense network of fibers with little ground substance.
Cartilage has cells distributed among fibers in a firm gel like ground substance. Cartilage is tough
but flexible, avascular, and without nerves.
Bone has cells distributed among abundant fibers in a solid ground substance containing minerals,
mostly calcium phosphate. Bone is organized in units, called osteons (formerly known as the
Haversian system). Eachosteon consists of a central canal, which contains blood vessels and nerves,
surrounded by concentric rings (lamellae) of hard matrix and collagen fibers. Branching off the central
canal at right angles are perforating canals. These canals consist of blood vessels that branch off the
central vessels. Between the lamellae are cavities (lacunae) that contain bone cells (osteocytes).
Canals (canaliculi) radiate from the central canal and allow nutrient and waste exchange with the
osteocytes.
Blood is composed of various blood cells and cell fragments (platelets) distributed in a fluid matrix
called blood plasma.

20. Tissue origin
All mature connective tissues originate from embryonic connective tissue. There are two kinds of embryonic
connective tissues:
Mesenchyme is the origin of all mature connective tissues.
Mucous connective tissue is a temporary tissue formed during embryonic development.
An epithelial membrane is a combination of epithelial and connective tissues working together to
perform a specific function. As such, it acts as an organ. There are four principle types of epithelial
membranes:
Serous membranes line interior organs and cavities. The serous membranes that line the heart, lungs,
and abdominal cavities and organs are called the pericardium, pleura, and peritoneum, respectively.
Mucous membranes line body cavities that open to the outside of the body. These include the nasal
cavity and the digestive, respiratory, and urogenital tracts.
Synovial membranes line the cavities at bone joints.
The cutaneous membrane is the skin.