spicule
/ˈspɪkjuːl
/noun
1 technical A minute sharp-pointed object or structure that is typically present in large numbers, such as a fine particle of ice.A general overview on the structural organization of the proteinaceous filament inside spicules is presented....
- The spicules of bone revealed the characteristic corallike branching.
- The sharp spots in the diffraction patterns shown in Fig.5 indicated that the protein units forming the central filaments inside the spicules must be organized with a very high degree of order.
1.1 Zoology Each of the small needle-like or sharp-pointed structures of calcite or silica which make up the skeleton of a sponge.Sponge spicules are also an abundant constituent of the rhythmites....
- Recently spicules from sponges of the class Hexactinellida have been identified in Ediacaran age rocks.
- Pillow lava and marine sponge spicules found in the contact zones between individual layers of the Columbia River Basalt suggest that these lava layers flowed out under water and that the water was ocean water, not freshwater from a lake.
2 Astronomy A short-lived, relatively small radial jet of gas in the chromosphere or lower corona of the sun.Although relatively small compared to full scale solar flares, spicules are interesting for the same reasons: they may contribute to the solar wind....
- Penetrating the chromosphere are spikes of gas that rapidly jet upwards and then fall back again; these are termed spicules.
Derivatives
spicular
- Locally there are ‘hints’ of a parallel fibrous, possibly spicular, structure in the normally irregularly crystalline microstructure of the trabeculae.
- However, in specimens in which the secondary rays are well developed, the spicular structure becomes complicated and the primary six-rayed spicule is difficult to discern.
- Subsequent microscopic study of the outer layer shows that, in a few specimens, patches of the microcrystalline material grade laterally into vestigial spicular fabric.
spiculate
- As I watched my films slide out of the processor, there it was in my left breast: a tiny spiculate smudge.
- Your photos show the heavily spiculate skin of the mantle and the tubercles very well.
- Shallow lobulation is observed and short thin spinule, deep lobulation or spiculate protuberance is not observed in the tumour edge.
spiculation
- Calcifications, size, location, edges, and spiculations were documented for each nodule.
- Architectural distortion, spiculation, and microcalcifications are rare (with the exception of ovarian carcinoma).
- Lobulation, spiculation, and satellite lesions all suggest an increased likelihood of malignancy.
Origin
Late 18th century: from modern Latin spicula, spiculum, diminutives of spica 'ear of grain'.