| nematoblast | <biology> A spermatocyte or spermoblast. Source: Websters Dictionary (01 Mar 1998) |
|---|---|
| nematocalyx | Origin: NL. See Nemato-, and Calyx. <zoology> One of a peculiar kind of cups, or calicles, found upon hydroids of the family Plumularidae. They contain nematocysts. See Plumularia. Source: Websters Dictionary (01 Mar 1998) |
| nematocera | <zoology> A suborder of dipterous insects, having long antennae, as the mosquito, gnat, and crane fly. Synonym: Nemocera. Origin: NL, fr. Gr, a thread + horn. Source: Websters Dictionary (01 Mar 1998) |
| nematocidal | Destructive to nematode worms. (05 Mar 2000) |
| nematocide | An agent that kills nematodes. Origin: nematode + L. Caedo, to kill (05 Mar 2000) |
| nematocyst | Stinging mechanism used for defence and prey capture by Hydra and other members of the Cnidaria (Coelenterata). It is located within a specialised cell, the nematocyte and consists of a capsule containing a coiled tube. When the nematocyte is triggered, the wall of the capsule changes its water permeability and the inrush of water causes the tube to evert explosively ejecting the nematocyst from the cell. The tube is commonly armed with barbs and may also contain toxin. (18 Nov 1997) |
| nematocyte | Stinging cells found in Hydra, used for capturing prey and for defence. There are four major types, containing different sorts of nematocysts: stenoteles (60%), desmonemes, holotrichous isorhizas and atrichous isorhizas. They differentiate from interstitial cells and are almost all found in the tentacles. (18 Nov 1997) |
| nematoda | A class of unsegmented helminths with fundamental bilateral symmetry and secondary triradiate symmetry of the oral and oesophageal structures. Many species are parasites. (12 Dec 1998) |
| nematode | Infection by the nematode Ascaris lumbricoides and is characterised by an early pulmonary phase related to larval migration and a later, prolonged intestinal phase. Adult worms are 15-40 cm in length and maintain themselves in the lumen of the small intestine. Infection occurs after ingesting eggs contained in contaminated food or more commonly, by transmission to the mouth by the hands after contact with contaminated soil. Treatment is with mebendazole or pyrantel pamoate. (27 Sep 1997) |
| nematode infections | Infections by nematodes, general or unspecified. (12 Dec 1998) |
| nematode sperm | The nematode Caenorhabditis elegans has an unusual amoeboid spermatozoon that is actively motile yet appears to lack both actin and tubulin. (18 Nov 1997) |
| nematodiasis | Infection with nematode parasites. (05 Mar 2000) |
| Nematodirella longispiculata | One of the thread-necked trichostrongyle nematodes in the small intestine of sheep, goats, reindeer, moose, musk ox, and pronghorn. (05 Mar 2000) |
| Nematodirus | The genus of thread-necked or thin-necked trichostrongyles; slender, relatively elongated nematodes occurring in herbivorous animals, usually in the small intestine. Generally, they are not believed to be highly pathogenic except in poorly fed, heavily infected animals. Species include: Nematodirus abnormalis, common in the U.S. And occurring in sheep, goats, camels, and mule deer. Nematodirus filicollis, occurring worldwide in sheep, goats, oxen, and various wild ruminants. Nematodirus helvetianus, in cattle, sheep, goats, and camels in Europe, Asia, and the Americas. Nematodirus lanceolatus, in sheep and pronghorns in the Americas. Nematodirus leporis, in domestic rabbits and wild cottontail rabbits in North America. Nematodirus spathiger, the most common, widespread, and abundant species, in sheep, cattle, camels, and other ruminants. (05 Mar 2000) |
| nematogene | <zoology> One of the dimorphic forms of the species of Dicyemata, which produced vermiform embryos; opposed to rhombogene. Origin: Nemato- + root of Gr. To be born. Source: Websters Dictionary (01 Mar 1998) |