Term
What are the types of bone cells(4)? |
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Definition
osteoprogenitor, osteoblast, osteocyte, and osteoclast |
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Term
Which bone cell is not found on the bone surface? |
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Definition
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Term
What is the function of osteoblasts? |
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Definition
synthesize organic components: osteoid tissue (collagen fibers and ground substance), and secrete alkaline phosphatase (calcium deposition) |
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Term
What enzyme is secreted by osteoblasts? |
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Definition
alkaline phosphatase; deposition of calcium salts |
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Term
What is the function of osteocytes? |
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Definition
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Term
Which bone cells have gap junctions? |
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Definition
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Term
What are the enzymes secreted by osteoclasts and the action of each? |
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Definition
carbonic anhydrase - decalcification of bone matrix; collagenase - break down collagen fibers |
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Term
Which hormone stimulates osteoclastic activity? |
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Definition
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Term
What do you know about Howship's lacuna? |
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Definition
A depression active sites (divet into the surface of the bone) |
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Term
What bone cell has a ruffled border? |
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Definition
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Term
What is the major organic component of bone matrix? |
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Definition
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Term
What are the main minerals of the bone matrix? |
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Definition
calcium phosphate and calcium carbonate |
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Term
What are the two forms of calcium phosphate? |
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Definition
hydroxyapitite crystals and calcium phosphate salts |
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Term
What do you know about Sharpey's fibers? |
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Definition
collagen fibers that connect periosteum to outer circumferential lammellae of compact bone |
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Term
What is the function of the periosteum? |
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Definition
outer surface of the bone; outer layer (dense irregular CT) blood vessels; inner layer (loose areolar CT) osteogenic cells |
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Term
What is the function of the endosteum? |
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Definition
osteogenic cells (make osteoblast, which make bone) |
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Term
Which bone is stronger: woven or lamellar? |
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Definition
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Term
What are 2 types of lamellar bone and its location? |
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Definition
Compact bone - shafts of long bones; spongey bone - flat and irregular bones |
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Term
What is the unit structure of compact bone? |
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Definition
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Term
Which canal is parallel to the long axis of bone? |
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Definition
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Term
What is the function of Volkmann's canals? |
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Definition
communication between blood vessels |
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Term
What is the function of bony canaliculi around osteocyte processes? |
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Definition
transmit interstitial fluid and nutrients |
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Term
What covers the surface of trabeculae of spongy bone? |
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Definition
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Term
Define intramembranous ossification |
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Definition
bone growth within a vascularized embryonic connective tissue (mesenchyme) |
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Term
What are some bones that ossify through intramembranous ossification? |
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Definition
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Term
Which zone contains degenerating cartilage cells? |
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Definition
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Term
Which cells lay down bone in the ossification zone? |
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Definition
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Term
What is the effect of estrogen on bone? |
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Definition
decreased osteoclast and increase osteoblast |
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Term
What is the effect of parathyroid hormone on bone? |
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Definition
stimulates osteoclasts and increases blood Ca++ |
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Term
What is the effect of thyrocalcitonin on bone? |
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Definition
lowers blood calcium level |
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Term
What is the effect of growth hormone on bone? |
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Definition
Pituitary; excess - giantism, or acromegaly; decrease dwarfism |
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Term
What is the effect of vitamin D deficiency on bone? |
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Definition
leads to defective absorption of Ca++ from the intestine and leads to rickets in children and osteomalacia in adults (soft but strong bones) |
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Term
What is the effect of vitamin C deficiency on bone? |
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Definition
defective collagen formation; scurvy (bones are rigid but weak) |
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Term
How does bone grow in width? |
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Definition
appositional growth by the osteoblasts |
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Term
How does bone grow in length? |
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Definition
activity of hyaline cartilage of epiphyseal plate |
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Term
Can bone brow by the interstitial method like cartilage? |
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Definition
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Term
What is the main mineral in bone matrix? |
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Definition
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