软骨和骨组织学和胚胎学.ppt

Cartilage and Bone,1. Cartilage: organ=Cartilage tissue+perichondrium,1) structure of cartilage tissue -cell: chondrocyte -cartilage matrix, chondrocyte: -Structure: LM embedded in cartilage lacuna peripheral cells: -small and immature -single and flattened central cell: -large and mature, -round and in group of 2-8 cells -small and round nucleus -basophilic cytoplasm -EM: rich in RER and Golgi complex,*isogenous group: several cells locates in one lacuna, which are derived from a single(same) parent cell, Cartilage matrix -ground substance: proteoglycan: -same to loose CT -there are more chondroitin sulfate distributed at the periphery of cartilage lacuna-called as cartilage capsule(basophilic) water -fiber: type and number of fiber depends on the type of cartilage,2) Classification: according to the fiber Hyaline cartilage: less collagenous fibril articular surface, rib cartilage, trachea and bronchi,Fibrous cartilage: large amount of collagenous fiber bundles cells are small and less intervertebral disc, symphysis pubis,Elastic cartilage: large amount of elastic fiber external ear, epiglottis,3) perichondrium two layers: -out layer: contain more fiber-protection -inner layer: more cells-osteoprogenitor cell(fusiform in shape),4) growth of cartilage -interstitial growth: inner chondrocyte proliferation produce fiber and matrix. immature cartilage -appositional growth: osteoprogenitor cellchondroblast chondrocyte produce fiber and matrix. growing and mature cartilage,2.Bone -consists of bone tissue, periosteum and endosteum, bone marrow,1) Bone tissue Cells:,a. osteoprogenitor cell: stem cell -structure: fusiform, small ovoid nucleus slight basophilic cytoplasm exist in periosteum and endosteum -function: differentiated into osteoblast and chondrocyte,b. osteoblast: -structure: LM: single layer of cuboidal or low columnar cell round nucleus basophilic cytoplasm located on the surface of bone tissue,EM: fine processes rich in RER, Golgi complex,-function: .synthesize bone collagen fiber and ground substance-osteoid .release matrix vesicle: 0.1um in diameter membrane-coated function: promote calcification,c.osteocyte -structure: flattened cell with multiple long thin processes located in bone lacuna and bone canaliculus basophilic cytoplasm adjacent cells connect in bone canaliculus by gap junctions -function: Maintain bone matrix,d. osteoclast -structure: LM: multinuclear large cell, 30-100um 6-50 nuclei acidophilic cytoplasm located at peripheral part of bone,EM: ruffled border-processes light zone: -under the ruffled border -microfilament primary lysosome, pinosome and secondary lysosome RER, mito. and Golgi -function: dissolve and absorb bone matrix,Bone matrix -organic matter: bone collagen fiber -collagenous fiber (type I collagen) ground substance: glycosaminoglycan,-inorganic matter: bone salts Hydroxyapatite crystal: Ca10(PO4)6(OH)2 pin-shaped longitudinal arranged *bone lamella: bone matrix arranged in layers at different direction,2) Architacture of long bone Long bone is an organ, made up of bone tissue(shaft and epiphyses), periosteum and endosteum, bone marrow, shaft: consists of compact bone a. circumferential lamella: /outer concentrically-arranged /inner around inner surface of bone,b. Haversian system (osteon): /cylindric structure, 3-5mm /central canal: N, BV, CT /Haversian lamella: 4-20 layers,c. interstitial lamella: /irregular lamella /remnant of Haversian or circumferential lamella *perforating canal: /transverse canal /connect with Haversian canal, epiphyses: composed of spongy bone -trabeculae: formed by parallelly-arranged lamella form a spongy-liked network -Bone marrow: hemopoietic tissue, periosteum and endosteum: CT membrane -periosteum: DCT outer layer:more fiber bundles form perforating fiber inner layer: