CONNECTIVE TISSUE
CHAPTER 3 – PART 6
CONNECTIVE TISSUE
 Connective
Tissue –
Connect body parts.
It is found everywhere
in the body.
 It is the most abundant
and wide distributed of
the tissue types.

COMMON CHARACTERISTICS OF
CONNECTIVE TISSUE
1.
Variation of blood supply
–
–
2.
Most connective tissues are well vascularized,
but there are exceptions.
Tendons and ligaments have poor blood supply
and cartilages are avascular. Therefore, these
structures heal very slowly.
Extracellular matrix
–
Connective tissues are made up of many
different types of cells plus varying amounts of
a nonliving substance found outside the cells,
called the extracellular matrix.
EXTRACELLULAR MATRIX
 The
extracellular
matrix has two main
elements:
A structureless
ground substance
2. Fibers
1.
GROUND SUBSTANCE OF THE
EXTRACELLULAR MATRIX
•
Composed of:
Mostly water
2. Some adhesion proteins
1.

3.
Serve as glue that allows the cells to attach
themselves to the matrix fibers embedded in the
matrix.
Large, charged polysaccharide molecules.
Trap water as they intertwine.
 As the abundance of these polysaccharide molecules
increases, they cause the matrix to vary from fluid to
gel-like to firm to rock-hard.

FIBERS OF THE EXTRACELLULAR MATRIX
 Various
types and
amounts of fibers are
deposited in the
matrix depending on
the connective tissue
type and include:
Collagen fibers (white)
2. Elastic fibers (yellow)
3. Reticular fibers (fine
collagen)
1.
CONNECTIVE TISSUE VARIATION
 All
connective tissue consists of living
cells surrounded by a matrix.
 Their major differences reflect fiber type
and the number of fibers in the matrix.
At one extreme, fat tissue is composed mostly
of cells, and the matrix is soft.
 At the opposite extreme, bone and cartilage
have very few cells and large amounts of hard
matrix, which makes them extremely strong.

CONNECTIVE TISSUE FUNCTIONS
1.
2.
3.
4.
Protecting
Supporting
Binding together other
body tissues
Serve as a water reservoir
(less known function)

Ground substance has the
ability to absorb large
amounts of water.
TYPES OF CONNECTIVE TISSUE
1.
2.
3.
4.
5.
Bone
Cartilage
Dense Connective Tissue
Loose Connective Tissue
Blood
BONE

Bone – Composed of
bone cells sitting in
cavities called lacunae
and surrounded by layers
of a very hard matrix that
contains calcium salts in
addition to large numbers of collagen
fibers.


Also called osseous tissue.
Because of its rocklike hardness, bone has
an exceptional ability to protect and
support other body organs.
CARTILAGE
 Less
hard and more
flexible than bone.
 It is found only in a few
places in the body.
THREE TYPES OF CARTILAGE:
Hyaline Cartilage – Has
abundant collagen fibers
hidden by a rubbery matrix
with a glassy, blue-white
appearance.
1.
–
–
–
Forms the supporting structures of the larynx
(voice box), attaches the ribs to the breastbone, and
covers the ends of bones where they form joints.
The skeleton of a fetus is made of hyaline cartilage,
but by the time the baby is born most of that
cartilage has been replaced by bone.
Most abundant and widespread in the body.
THREE TYPES OF CARTILAGE
Fibrocartilage –
Highly compressible
2.

Forms the cushionlike
disks between the
vertebrae of the spinal
column.
Elastic Cartilage –
Very elastic
3.

Found where structure
with elasticity is desired
such as the external
ear.
DENSE CONNECTIVE TISSUE
•
•
•
•
•
Has collagen fibers as its main
matrix element.
Crowded between the collagen
fibers are rows of fibroblasts
that manufacture the fibers.
Also called dense fibrous tissue.
Forms strong, ropelike structures.
Examples:
Tendons: Attach skeletal muscles to bones.
Ligaments: Connect bones to bones.
1.
2.
•
3.
More stretchy and contain more elastic fibers than
tendons.
Also makes up the lower layers of the skin
(dermis) where it is arranged in sheets.
LOOSE CONNECTIVE TISSUE
 Softer
and have more
cells and fewer fibers
than any other
connective tissue type
except blood.
 Two types:
Areolar Tissue
2. Adipose Tissue
1.
AREOLAR TISSUE
 Areolar
Tissue –
Soft, pliable “cobwebby”
tissue that cushions and
protects the body organs
it wraps.
Most widely distributed connective tissue
variety in the body.
 Functions as a universal packing tissue and
connective tissue “glue” because it helps to
hold the internal organs together and in
their proper position.

AREOLAR TISSUE
•
Because of its loose and
fluid nature, areolar
connective tissue provides
a reservoir of water and
salts for the surrounding tissues.
–
–
All body cells obtain their nutrients from areolar CT
and release their wastes into this “tissue fluid.”
When a body region is inflamed, the areolar tissue in
the area soaks up the excess fluid like a sponge and
the area swells and becomes puffy, a condition known
as edema.
• Many phagocytes wander through this area scavenging
for bacteria, dead cells, and other debris, which they
destroy.
ADIPOSE TISSUE
•
Adipose Tissue –
Commonly called fat;
areolar tissue in which
fat cells predominate.
–
A droplet of stored
oil occupies most of
the fat cell’s volume
and compresses the
nucleus, displacing it
to one side.
ADIPOSE TISSUE
•
Functions:
1.
2.
3.
Adipose tissue forms the
subcutaneous tissue
beneath the skin, where it
insulates the body and
protects it from extremes of
both heat and cold.
Protects some organs
individually. Fat cushions
the kidneys and eyeball
sockets.
Fat deposits in the body (hips
and breasts), where fat is
stored and available for fuel
if needed.
RETICULAR CONNECTIVE TISSUE
 Reticular
Connective Tissue
Type of loose irregular
connective tissue.
 Has a network of
reticular fibers.



Reticular fibers are
synthesized by fibroblasts
called reticular cells.
Forms a soft skeleton
or internal supporting
framework (stroma) to support the lymphocytes
in lymphoid organs (lymph nodes, red bone
marrow, and spleen).
BLOOD
 Blood
– Vascular tissue
Consists of blood cells,
surrounded by a nonliving,
fluid matrix called blood
plasma.
 The fibers of blood are soluble protein molecules
that become visible only during blood clotting.
 Blood is quite atypical as connective tissues go.
 Blood is the transport vehicle for the
cardiovascular system.


Carries nutrients, wastes, respiratory gases, and
many other substances throughout the body.