1. CARTILAGE Cartilage is a specialized type of C.T. with a rigid matrix. Cartilage is a specialized type of C.T. with a rigid matrix. Cartilage is nonvascular. Cartilage is nonvascular. 3 Types: 3 Types: –Hyaline cartilage. –Elastic cartilage. –Fibrocartilage.

2. Hyaline Cartilage 1- Perichondrium: –Vascular CT membrane formed of 2 layers: »Outer fibrous layer: dense fibrous CT. »Inner chondrogenic layer: contains chondroblasts. They secrete cartilage matrix and give rise to chondrocytes.

3. Hyaline Cartilage 2- Cells (Chondrocytes): –Found in spaces called lacunae. –Young chondrocytes are small & present singly in their lacunae. –Mature chondrocytes are large, and are found in groups of 2, 4 or 6 cells in their lacunae (cell nests). 3- Matrix: –Homogeneous and basophilic.

4. Hyaline Cartilage

5. Sites of hyaline cartilage: Sites of hyaline cartilage: –Costal cartilages. –Articular cartilages. –Respiratory cartilages: Nose, larynx, trachea & bronchi.

6. Elastic Cartilage Similar to hyaline cartilage + elastic fibres in the matrix. Similar to hyaline cartilage + elastic fibres in the matrix. Sites: Sites: –External ear. –Epiglottis.

7. Fibrocartilage No perichondrium. No perichondrium. Rows of chondrocytes in lacunae separated by parallel bundles of collagen fibers. Rows of chondrocytes in lacunae separated by parallel bundles of collagen fibers. Sites: Sites: –Intervertebral discs.

8. Sites of Cartilage

9. BONE Bone is a specialized type of CT with a hard matrix. Bone is a specialized type of CT with a hard matrix. Types: 2 types Types: 2 types –Compact and spongy bone. Components: Components: –Bone Cells: 4 types. –Bone Matrix: hard because it is calcified. Functions: Functions: –body support. –protection of vital organs as brain & bone marrow. –calcium store.

10. Bone Cells 1- Osteoblasts: –in periosteum & endosteum. –Function: They secrete the bone matrix & deposit Ca salts in it and change to osteocytes.

11. Bone Cells 2-Osteocytes : –Branched cells. –Present singly in lacunae. Their branches run in the canaliculi. –Origin: osteoblasts. –Function: They maintain the bone matrix.

12. Bone Cells 4- Osteoclasts: –Large multinucleated cells on bony surfaces, in Howship’s lacunae. –Cytoplasm is rich in lysosomes. –Origin: blood monocytes. –Function: bone resorption.

13. Compact Bone It is found in the diaphysis of long bones. It is found in the diaphysis of long bones. Consists of: Consists of: 1-Periosteum: »Outer fibrous layer. »Inner osteogenic layer. 2-Endosteum. 3-Bone Lamellae.

14. Compact Bone Bone Lamellae: 1- Haversian Systems (Osteons): –Longitudinal cylinders. –Each is formed of concentric bone lamellae & a Haversian canal, running in the center. –Volkmann’s canals connect the Haversian canals together. 2. External Circumferential Lamellae. 3- Internal Circumferential Lamellae. 4- Interstitial Lamellae: between osteons. 1 2 3 4

15. Compact Bone Bone Lamellae: 1. External Circumferential Lamellae 2- Haversian Systems (Osteons): –Longitudinal cylinders. –Each is formed of concentric bone lamellae & a Haversian canal, running in the center. –Volkmann’s canals connect the Haversian canals together. 3- Interstitial Lamellae: between osteons. 4- Internal Circumferential Lamellae

16. Spongy (Cancellous) Bone In epiphysis of long bones & flat bones. In epiphysis of long bones & flat bones. Consists of : Consists of : 1.Periosteum. 2.Endosteum. 3.Irregular bone trabeculae. 4.Many irregular bone marrow spaces. No Haversian systems (osteons). No Haversian systems (osteons).

17. PRACTICAL

18. Hyaline Cartilage

19. Elastic Cartilage

20. Compact Bone

21. Spongy Bone