from The American Heritage® Dictionary of the English Language, 4th Edition
- n. The spongy, porous, bony tissue between the hard outer and inner bone layers of the cranium.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. The thin layer of soft, spongy or cancellate tissue between the bone plates which constitute the skull.
from the GNU version of the Collaborative International Dictionary of English
- n. The soft, spongy, or cancellated substance between the plates of the skull.
from The Century Dictionary and Cyclopedia
- n. In anatomy, the light spongy substance or open cancellated or reticulated structure of bone between the hard dense inner and outer tables of the cranial bones.
- n. In botany, the parenchyma of a leaf, lying between the two epidermal surfaces. Also called meditullium.
The diploe is the most porous, the softest, and most cavernous part.
The bone at the middle of the head is double, the hardest and most compact part being the upper portion, where it is connected with the skin, and the lowest, where it is connected with the meninx (dura mater); and from the uppermost and lowermost parts the bone gradually becomes softer and less compact, till you come to the diploe.
In many old skulls, however, the diploe is wanting altogether, and the two tables are amalgamated, and often very thin.
The tough outer table is more difficult to cut than the softer and more vascular diploe, and the inner table is denser than either, but more brittle.
Now retract the pyramid, lest it injure the dura-mater; continue the rotary motion, holding the instrument perpendicularly to the bone, withdrawing from time to time, to clean its teeth with the brush and to enable the Surgeon to sound the depth of the groove; -- and penetrate both the diploe and the internal table.
The division of the diploe can be readily recognized by the ease with which the instrument penetrates its substance and the bloody detritus which escapes.
The spongy middle plate must, like the diploe of the skull, have served to deaden the vibrations of a blow dealt from the outside.
It consisted of three plates, or rather, like the human skull, of two solid plates, with a _diploe_ or spongy layer between.
It consisted of its two well-marked tables of solid bone, corresponding in their dermal character, the outer to the cuticle, the inner to the true skin, and the intermediate cellular layer to the _rete mucosum_; but bearing an unmistakable analogy also, as a mechanical contrivance, to the two plates and the _diploe_ of the human skull.
Classification as to Structure: a. Spongy - made up of bony processes called trabeculae giving it a porous appearance; found in the epiphysis and metaphysic of long bones, diploe of flat bones and in the medullary cavities b.
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