Ass.Lec. Rafah Saleem
2.Cartilage : Jelly-like matrix (chondroitin sulfate) containing collagen
and elastic fibers and chondrocytes surrounded by a membrane called
the perichondrium.
a. Hayline cartilage : Amorphous but firm matrix; collagen fibers form
an imperceptible network; chondroblasts produce the matrix and when
mature(chondrocytes) lie in lacunae.
Location: Forms most of the embryonic skeleton; covers the ends
of long bones in joint cavities; forms costal cartilages of the ribs;
cartilages of the nose, trachea, and larynx.
b. Elastic cartilage : Similar to hyaline cartilage, but more elastic fibers
in matrix.surrounded by perichondrium .
Location: Supports the external ear (pinna); epiglottis .
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Ass.Lec. Rafah Saleem
c. Fibrocartilage: Matrix similar to but less firm than that in hyaline
cartilage; thick collagen fibers predominate. And there is no
perichondrium .
Location: Intervertebral discs;pubic symphysis; discs of knee
joint.
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Ass.Lec. Rafah Saleem
3. Bone (osseous tissue) :
Connective tissue that
provides mechanical support and protection
, Very important storage
of calcium,and hematopoiesis(blood cell formation) .
There are two of bones :
Compact bone : is composed of osteocytes(bone cells) within
lacunae arranged in concentric circles called lamellae , This
surround a central canal; complex is called Haversian system.
Canaliculi connect osteocytes to central canal and to each other.
Haversian canal place for the nerve blood and lymphatic
.
vessels There are some bone lamellae and some lacunae are
present among the Haversian system ,and are not arranged
around Haversian canals such as these are called Non-Haversian
system.
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Ass.Lec. Rafah Saleem
Spongy bone :
Spongy bone is the structure located deep in compact
bone. It is made up of thin trabeculae that align along the
stress lines. This helps the bone to resist stress while
maintaining its light weight.
There are no osteons present in spongy bone; however,
its trabeculae contain lamellae, lacunae
interconnected by canaliculi, and osteocytes .There are
three designated cell are associated with this tissue :1.Osteoblasts :are recognized by their cuboidal or
polygonal shape and their aggregations single layer of cells
.
2.Osteocytes :are differentiated osteoblasts ,occupies
spaces or lacuna.
3.Osteoclast:rest directly on the surface of the bone where
resorption is take place .
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