The Cartilage and Bone

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 .
Ass.Lec. Rafah Saleem
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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.
Ass.Lec. Rafah Saleem
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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.