What's the difference between spicule and tetraxile?

Spicule

Definition:

(n.) A minute, slender granule, or point.
(n.) Same as Spicula.
(n.) Any small calcareous or siliceous body found in the tissues of various invertebrate animals, especially in sponges and in most Alcyonaria.

Example Sentences:

(1) Almost nothing is known about nature and timing of the embryonic cues which induce or initiate spicule formation by these cells.
(2) X-ray examination disclosed a spicule formation surrounding the osteolytic focus in the mandible.
(3) Bone spicule pigmentation increased in 41 of 76 patients for whom we could make comparisons over a three-year interval (54%).
(4) In morphology it is similar to D. bargusinica Skrjabin 1917, D. campanae Anderson 1959, D. dollfusi Anderson 1959, and D. epsilon Johnston and Mawson 1940, but can be separated from these species by combinations of trident size and spicule size and morphology.
(5) Characteristics features of this species (only males were found) are the small size of body, size and type of spicules, shape of tail and arrangement of caudal papillae.
(6) Two different types of spicules in male Enterobius were also observed in Korea.
(7) The border was assessed for a smooth, irregular, or spiculated margin.
(8) The authors had under observation 21 patients with diastematomyelia--a rare congenital disease marked by the formation of a bony spicule in the vertebral canal, which splits the spinal cord and its meninges.
(9) In both studies, the poikilocytes were identified as echinocytes, spiculated erythrocytes, and schizocytes.
(10) The girdle epidermis of adult Mopalia muscosa secretes several types of structures, including calcareous spicules and innervated hairs.
(11) Deposits consisted of dense aggregations of randomly entangled spicules spreading within bundles of collagen fibrils.
(12) From the above results, it was evident that both the matrix vesicles derived from functioning osteoblast, and the vesicular structures derived from the degenerated or dead cells concurrently phagocytosing spicules and collagen fibrils were involved in the initial calcification process of the membranous bone in vitro.
(13) We present the first two cases of vertebral metastases from prostatic carcinoma with spicule formation giving rise to osseous spinal stenosis and neurological deficits, best demonstrated by CT.
(14) Their dendrites also bear fine spicules and usually reach the tectal surface.
(15) Methylmercuric chloride produced an irregularity of cell shape with spicules including the final stage of spherocytes.
(16) Three male siblings, born of nonconsanguineous parents, manifested the characteristic paravenous bone spicule accumulation typically seen in pigmented paravenous chorioretinal atrophy.
(17) They differ from D. ramachandrani in their location in the host, the tail length, the shape of the spicules, and in the number of caudal papillae.
(18) At the same time the red cells became crenated and developed thorny spicules (echinocytes).
(19) We believe that these spicules correspond to the reorganization of the stroma along the edges of the corneal incision.
(20) Despite the variability of some characters such as length of tail and spicules, arrangment of caudal papillae, these species are well characterized by a set of elements, the two most important of which are the female cuticle and the anatomy of the microfilariae.