Composition Text Fig. I.12
a. Cortex - outer mantel of compact bone; responsible for shape
b. Cancellous - inner supportive layer of trabeculated "spongy" bone; responsible for strength
c. Medullary cavity - innermost "hollow" area filled with marrow; may be "yellow" serving as a fat storage department or "red" serving as a blood forming organ
d. Periosteum - connective tissue layer surrounding bone which:
- 1) sends fibers (Sharpey) into the bone for anchoring purposes
- 2) possesses an inner layer of osteoprogenitor cells which participate in bone growth and repair
- 3) is highly innervated
NOTE: It is the presence of composition and function which provide landmarks of relief on bone in response to stress exerted on the periosteum by tendons.
e. Endosteum - lines medullary spaces, is less well developed than periosteum, however, does possess osteoprogenitor cells.