Supportive tissue has a rigid matrix. It forms the endoskeleton. It is of two types.:
I). Cartilage. II). Bone
(Describe the structure of cartilage? Add a note on its growth? 4 marks)
1. Cartilage is also called gristle.
2. Study of cartilage is called chondrology.
3. It forms endoskeleton of cyclostomes and cartilaginous fishes.
4. In bony vertebrates, it forms the embryonic skeleton.
5. Cartilage is surrounded by pericardium.
6. Blood vessels are absent in cartilage.
7. It I rich in collagen fibres and elastic fibres.
8. During formation, chondroblasts secrete the matrix, and the cells are enclosed in spaces called lacunae.
9. Each lucana may contain up to eight chondrocytes.
10. Growth of cartilage is either interestitial or appositional.
11. The interstitial growth, regulating from the mitotic division and reactivation of preexisting chondrocytes.
12. The appositional growth, resulting from the differentiation of perichordial cells.
Describe the three types of cartilage? 4 marks.
Cartilage is differentiated into three kinds. They are hyaline cartilage, elastic cartilage,fibrocertilage.
It is bluish white and translucent.
Collagen is in the form of delicate fibrils.
Perichondrium is absent in articular cartilages and epiphyseal plates.
It is the weakest of the three types of cortilage.
Location: Walls of nose, larynx, trachea, bronchoii, in the ventral ends of vibs, costal cartilage, epiphyeal plate, articular cartilages in joints, and embryonic skeleton of bony vertebrates.
Matrix have more elastic fibres than collagen fibres.
It is yellowish.
Perichondrium is present.
It provides strength and elasticity.
Location: Ear pinna, epiglottis, eustachin tube.
Matrix contain dense net work of collagin fibres.
Perichondrium is absent.
It provides strength and rigidity.
It is the strongest of all the three types of cartilage.
Location: Intervertibral discs, pubic symphosis.