connective tissues

:The Skeletal Tissues- 2
• These tissues compose the skeleton. They are
either
• cartilage
• bone.

I-Cartilage
Is a specialized form of connective tissue in which :
the extracellular matrix has a firm consistency, it is
essential for the development and the growth of
long bones.
It consist of cells (Chondrocytes) and an extensive
extracellular matrix composed of fibers and ground
substance. The cells are located in cavities called
lacuna, also it surrounded by the perichondrium
which is a capsule like sheath of dense connective
tissue.
Three forms of cartilage have evolved,each exhibiting
variations matrix composition.
Hyaline Cartilage )-1(
Examine a T. S. of the trachea :
•the matrix is solid and clear
•the chondroblasts or chondrocytes are
arranged either singly or in-groups of twos,
fours or rarely eighths.
•the single or group of chondroblasts lies in
a clear capsule or lacuna .
• the presence the perichondrium.
• A, B,C,
progressive
stages in
chondrocytes
differentiation
Cap: capsule
Ch : chondrocytes
L: lacuna
P : perichondrium

(b)- Fibrous cartilage
Has matrix rich
• in white fibers and
there is no
perichondrium, it is
found in the
intervertebral discs
in mammals.



(c) - Elastic cartilage.Has a matrix rich in yellow fibers and
surrounded by perichondrium it is found in the ear pinna
and epiglottis of mammals