vallia
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Following a fracture of the humerus, an adult patient has a biopsy of the healing area. Which of the
following types of bone will the biopsy most likely show?
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A. Cancellous
B. Compact
C. Spongy
D. Trabecular
E. Woven
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| Cedrick
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e.-woven
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| blueocean
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The process of healing a fracture starts when the injured bone and surrounding tissues bleed. The blood coagulates to form a blood clot situated between the broken fragments. Within a few days blood vessels grow into the jelly-like matrix of the blood clot. The new blood vessels bring white blood cells to the area, which gradually remove the non-viable material. The blood vessels also bring fibroblasts in the walls of the vessels and these multiply and produce collagen fibres. In this way the blood clot is replaced by a matrix of collagen. Collagen's rubbery consistency allows bone fragments to move only a small amount unless severe or persistent force is applied.
At this stage, some of the fibroblasts begin to lay down bone matrix (calcium hydroxyapatite) in the form of insoluble crystals. This mineralization of the collagen matrix stiffens it and transforms it into bone. In fact bone is a mineralized collagen matrix; if the mineral is dissolved out of bone, it becomes rubbery. Healing bone callus is on average sufficiently mineralized to show up on X-ray within 6 weeks in adults and less in children. This initial "woven" bone does not have the strong mechanical properties of mature bone. By a process of remodelling, the woven bone is replaced by mature "lamellar" bone. The whole process can take up to 18 months, but in adults the strength of the healing bone is usually 80% of normal by 3 months after the injury.
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| docarchana
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by the explanation, i think woven bone is the better choice. right????
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| vallia
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yes
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| blueocean
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yes
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| kingusmle
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right blue ocean..where did u get this info
thanx
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