Cartilage and Bone Tissue 软骨组织和骨组织

1. Cartilage and Bone Tissue软骨组织和骨组织 Department of Histology and Embryology Medical college in Three Gorges University

2. Cartilage 软骨 Cartilage is composed of cartilage tissue(软骨组织） and the perichondrium（软骨膜）.

3. Chondrocytes 软骨细胞 Cell Cartilage tissue fibers Extracellular matrix Ground substances

4. Within the ground substance are embedded varying proportions of collagen and elastic fibres giving rise to three main type of cartilage: hyaline, fibrocartilage and elastic cartilage.

5. Cartilage cells 软骨细胞: The cells of cartilage are called chondrocytes. They lie in spaces or lacunae present in the matrix. At first the cells are small and show the features of metabolically active cells. This cell is also called as chondroblasts or embryonic cartilage producing cells.As the cells mature, they enlarge and be in group.

6. Ground substance: The ground substance of cartilage is made up of complex molecules containing proteins and carbohydrates（碳水化合物） (proteoglycans 蛋白多糖 ) these molecules form a meshwork which is filled by water and dissolved salts.

7. Fibres of cartilage: 1.Collagen fibers: type II collagen: hyaline cartilage type I collagen: the normal collagen fiber fibrocartilage, and the perichondrium, 2.Elastic fibers are in the Elastic cartilage

8. Hyaline cartilage 透明软骨

9. HC is the most common type of cartilage found in the nasal septum, larynx ,tracheal rings, most articular surfaces and the sternal ends of the ribs etc.

10. perichondrium Evident: an inner, strongly basophilic zone a narrow, pale stained peripheral zone

12. Isogenous cell group

13. Chondrocytes: lacuna area housing the cell • The cells are small present in single in the Periphery. • Towards the center of a mass of HC, the chondrocytes are large and are usually present in groups (of two or more ),these cells are called cell-nests (or isogenous cell groups).

14. What is the structure between the chondrocytes

15. an amorphous matrix of ground substance reinforced by collagen fibres • The deep staining matrix around cell or cell nests is newly formed and is called the territorial matrix or lacunar capsule. Their tiny matrix enclosed compartments are termed lacunae. (occupy space)

16. chondrocytes Extracellular matrix FCh

17. The matrix of HC appears fairly amorphous since the ground substance and collagen have similar refractive properties.or its intercellular substance appears to be homogeneous. We cannot identified the fiber in the light microscope with common method stained preparation of the cartilage.

18. Fibrocartilage

19. Fibrocartilage, unlike hyaline and elastic cartilage, does not possess a perichondrium and its matrix possesses type I collagen. • Distribution:the intervertebral discs(椎间盘）, • some Articular cartilage 关节软骨, • the pubic symphysis 耻骨联合,etc.

21. Elastic cartilage

22. The histological structure of EC is similar to that of hyaline cartilage, its elasticity, however, being derived from the presence of numerous bundles of branching elastic fibres. • Distribution: (1)in the external ear and external auditory canal外耳道 (2)the epiglottis会厌, parts of the laryngeal cartilage 喉软骨

24. Bone Tissue

25. It is composed of cells and a predominantly collagenous extracellular matrix (type I collagen ) called osteoid 类骨质which becomes mineralized by the deposition of calcium hydroxyapatite羟磷灰石, which produce an extremely hard tissue capable of support and protecting (rigidity and strength).

26. Bone and bone tissue骨和骨组织: • Bone are an organ,and bone tissue is the structural component of bones. • Bone consist of bone tissue and other connective tissue ,including hemopoietic 造血的 tissue, fat tissue, blood vessels, and nerves. • Bone is classified as either compact (dense ) or spongy (cancellous). To 49

28. Osteoblast 成骨细胞 Osteocyte骨细胞 Osteoclast 破骨细胞 osteoprogenitor cell 骨原细胞 Cells Elements of bone tissue Fibers-collagen fibers Extracellular matrix Ground substances: the mineral Calcium phosphate

29. The cells of bone: • Osteoblast 成骨细胞–which synthesize osteoid and mediate its mineralisation; they are found lined up along bone surface. • Osteocytes骨细胞-which represent largely inactive osteoblasts trapped within formed bone; they may assist in nutrition of bone.

32. canaliculi lacuna

33. Bone lacuna骨陷窝: cell body of the osteocyte. • The canaliculi 骨小管are occupied by delicate cytoplasmic processes of osteocytes, Spreading out from the lacuna. • (filled in tissue fluid).

34. Osteoclasts破骨细胞-phagocytic cells which are capable of eroding bone and which are important, along with osteoblasts, in the constant turnover and refashioning of bone. Osteoclasts are multinucleate phagocytic cells derived from the macrophage-monocyte cell line

38. Osteoprogenitor cell 骨祖细胞： The osteoprogenitor cell is a resting cell that can transform into an osteoblast and secrete bone matrix. It is found on the external and internal surfaces of bones. They resemble fibroblast in appearance.

39. Extracellular matrix : The feature that distinguishes bone from other connective tissue is the mineralisation of its matrix,which produce an extremely hard tissue capable of support and protecting.The mineral is calcium phosphate in the form of hydroxyapatite crystals羟磷灰石.

40. Composition • fiber:collagen fiber (I) Ground substance Glycosaminoglycans Proteoglycans Fibers and matrix Organic constituent Chemical constituents Calcium phosphorous other ions Inorganic constituent

41. According to the arrangement of the matrix in the bone tissue: There are several kind of lamellae: concentric lamellae 同心圆排列的骨板 circumferential lamellae 环状骨板 interstitial lamellae 间骨板

42. Lamellar bone:板层骨 or 骨板：When we examine the structure of any bone of an adult, we find that it is, made up of layers or lamellae. this kind of bone is called lamellar bone. Each lamellus is a thin plate of bone consisting of collagen fibers and mineral salts that are deposited in a gelatinous ground substance.

43. between adjoining lamellae we see small flattened spaces or lacunae which contain osteocytes.

44. Diaphysis 骨干 Epiphysis 骨骺 Spongy bone and compact bone

45. Structure of cancellous bone:(spongy松质骨) The bone plates or rods that form the meshwork of cancellous bone are called trabeculae. Each trabeculus is made up of a number of lamellae between which there are lacunae containing osteocytes. Canaliculi containing the processes of osteocytes, radiate from the lacunae.

46. The trabeculae enclose wide spaces which are filed in by bone marrow. They receive nutrition from blood vessels in the bone marrow. • Spongy bone is distributed mainly in epiphysis of long bone.

48. Structure of compact bone密质骨:(dense) When we examine a section of compact bone we find that this type of bone is also made up of lamellae.It is constitute the main parts of diaphysis.

49. According to the arrangment of lamellae, there are several kind of lamellae: circumferential lamellae 环骨板 concentric lamellae 同心圆骨板 interstitial lamellae 间骨板

50. ( 1 )circumferential lamellae环骨板: The outer circumferential lamellae are just deep to the periosteum, forming the outermost region of the diaphysis and contain Sharpey’s fibres anchoring the periosteum to the bone.