BONE
Bone
is the main component of the skeleton in the adult human. Like cartilage, bone
is a specialized form of dense connective tissue. Bone gives the skeleton the
necessary rigidity to function as attachment and lever for muscles and supports
the body against gravity.
Two
types of bone can be distinguished macroscopically:
- Trabecular
bone (also
called cancellous or spongy bone) consists of delicate bars and sheets
of bone, trabeculae, which branch and
intersect to form a sponge like network. The ends of long bones (or epiphyses) consist mainly of trabecular bone.
- Compact
bone does
not have any spaces or hollows in the bone matrix that are visible to
the eye. Compact bone forms the thick-walled tube of the shaft (or diaphysis) of long bones, which surrounds the
marrow cavity (or medullary cavity). A
thin layer of compact bone also covers the epiphyses of long bones.
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Bone
is, again like cartilage, surrounded by a layer of dense connective tissue,
the periosteum. A thin layer of cell-rich
connective tissue, the endosteum, lines the
surface of the bone facing the marrow cavity. Both the periosteum and the
endosteum possess osteogenic potency. Following
injury, cells in these layers may differentiate into osteoblasts
(bone forming cells) which become involved in the repair of damage to the
bone.
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Title:
Bone is the main
by:
om
at
2013-02-15T03:00:00+07:00
Rating: 4.8
of 5 Reviews
Bone is the main