1、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
2、 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 chondr
3、oitin 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, trache
4、a 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: mor
5、e cells- osteoprogenitor cell(fusiform in shape) 4) growth of cartilage -interstitial growth: inner chondrocyte proliferation produce fiber and matrix. immature cartilage -appositional growth: osteoprogenitor cell chondroblast chondrocyte produce fiber and matrix. growing and mature cartilage 2.Bone
6、 -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: -
7、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 membr
8、ane-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: L
9、M: 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 matri
10、x 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) A
11、rchitacture 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 s
12、tructure, 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 paralle
13、lly-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: rich in BV, N and osteoprogenitor cells -endosteum: thin, a layer of osteoprogenitor cell and CT -function: provide nutrition and osteoblast for bone growth and repairing 3) osteogenesis Self study!
