Term
| 2 mechanisms of bone formation |
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Definition
| Intramembranous: mesenchymal CT changes into bone, Endocondrial: cartilage is replaced by bone |
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Term
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Definition
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Term
| Describe how age relates to microscopic structure |
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Definition
| immature or woven bone: very cellular, irregular matrix lower mineral content, mature or lamellar bone: matrix is arranged in layers bone may be spongy AKA trabecular cancellous (composed of spicules) or compact |
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Term
| what type of growth does bown share with cartilage |
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Definition
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Term
| What defining characteristic does bone differ then cartilage |
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Definition
| bone is extremely vascular where cartilage is avasculater almost by definition |
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Term
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Definition
| (shaft) compact outside marrow cavity inside, red marrow is the site of blood cell formation or hematopoiesis, yellow marrow is filled with adipose CT |
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Term
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Definition
| in between epiphysis and diaphysis |
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Term
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Definition
| compact outside spongy bone inside |
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Term
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Definition
| is a line growth has stopped separates epiphesys from diaphsys |
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Term
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Definition
| covers outer suface of bone extept for articular surfaces similar in layer to cartilage outer layer of FECT and inner isteogenic layer |
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Term
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Definition
| lines marrow cavity ie all internal surfaces of bone, composed of a single layer of osteoblasts or osteogenic cells |
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Term
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Definition
| covers articular surgaces made of hyaline cartilage not cover by perichondrium |
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Term
| Describe the blood supply |
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Definition
| vessels in the periostium bcome entrapped as bone is being laid down; tge become vessels within canals of mature bone, Nutrient vessels: enter the diaphysis of compact bone supply marrow cavity Epiphyseal vessels: enter near epiphyseal plate, supply epihysis |
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Term
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Definition
| abundant sensory nerves in periosteum but not to bone cells. Vasomotor nerves accompany blood vessels with in the bone |
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Term
| briefly describe the acrhetecture of flat bone |
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Definition
| inner and out tables of relatively thick compact bone Diploe: spongy bone between the tables thickness varies with the specific bone, periosteum: outer surce is percranium, inner surface is part of the dura mater of the brain |
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Term
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Definition
| osteoblast or their precursors form a row of cuboidal cells on surfaces of bone both periosteal and endosteal surfaces, nucleus: frequently located on side away from bone, prominent nucleolus cytoplasm: very basophilic due to extensive RER hematoxophilic, frequently a negative golgi image is seen numerous mitochondrial |
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Term
| Describe the mechonisms of boen deposition |
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Definition
| 1st oisteoid is synthesized by osteoblasts: collagen type 1 fibers and ground substance primarily chondotin sulfate, 2nd ossification of osteoid then occurs from osteoblast secreting alkalin phophatase: this causes calcium to precipitate on osteoid along the collagen fibers |
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Term
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Definition
| osteoblast that has become completely surrounded by bone matrix lie in lacunae as doe chondrocytes. Shaped like a flattended ovoid with long processes extending from it though canaliculi in the bone toward other osteocytes function to transport materials between blood and bone to maintain surrounding matrix, gap junctions maintain cytoplasmic continuity |
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Term
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Definition
| large cells with up to 15-20 nuclei, located on the surface of bone frequenlty in depressions called howships lacunae; cell is dirived from monocytes in bone marrow, involved with bone resorption view proteolutic enzyme (acid phosphatase) Description: nuclei resemble those of osteoblast and osteocytes prominant nucleolus, Cytoplasm: frothy or vacuolated, surface facing bone is deeply ruffled and highly active, contains lysosomal granules of acid phosphatase |
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Term
| intercellular matrix of bone 2 portions |
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Definition
| organic portion about 35% of dry weight; inorganic portion about 65% of dry weight |
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Term
| organic portion role make up |
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Definition
| crompised of collagen type 1- 90% of organic matrix; formed by osteoblasts, GAGs primarily chondrotic sulfate, cements fibers compsed of less chondroitin then cartilege therefore matrix appears mor acidophilic (eosinophilic pink) than cartilage functions: provides bone with great toughness and reiliency flexibility |
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Term
| inorganic portion role and make up |
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Definition
| 1) crystals resembling hydroxyapatite, calcium ions, phophate ions, some citrate carbonate, deposition as slender needles along collagen fiber, function: provides bone with hardness |
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Term
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Definition
| referes to macroscpoic structure of bone |
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Term
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Definition
| refers to microscopic structure of boen |
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Term
| intramembranous vs endochondral |
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Definition
| refers to the two mechanisms of bone formation |
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