oligoglia

オリゴグリア

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2016/01/06 01:03:59」(JST)

wiki en

[Wiki en表示]

This article is about the group of worms. For the plant genus, see Oligochaeta (plant).

Oligochaeta
Earthworm (Lumbricus terrestris)
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Oligochaeta
Subclass:	Diplotesticulata
Orders
Haplotaxida Lumbriculida Moniligastrida

Oligochaeta /ˌɒlɨɡɵkˈiːtə/ is a class of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, and including all of the various earthworms. Specifically, the oligochaetes /ˈɒlɨɡɵkˈiːts/contain the terrestrial megadrile earthworms (some of which are semiaquatic or fully aquatic), and freshwater or semiterrestrial microdrile forms, including the tubificids, pot worms and ice worms (Enchytraeidae), blackworms (Lumbriculidae) and several interstitial marine worms.

With around 10,000 known species, the Oligochaeta make up about half of the phylum Annelida. These worms usually have few setae (chaetae) or "bristles" on their outer body surfaces, and lack parapodia, unlike polychaeta.

Common characteristics

Oligochaetes are well-segmented worms and most have a spacious body cavity (coelom) used as a hydroskeleton. They range in length from less than 0.5 mm (0.020 in) up to 2 to 3 metres (6.6 to 9.8 ft) in the 'giant' species such as the giant Gippsland earthworm and the Mekong worm Amynthas mekongianus (Cognetti, 1922).

The first segment, or prostomium, of oligochaetes is usually a smooth lobe or cone without sensory organs, although it is sometimes extended to form a tentacle. The remaining segments have no appendages, but they do have a small number of bristles, or chaetae. These tend to be longer in aquatic forms than in the burrowing earthworms, and can have a variety of shapes.

Each segment has four bundles of chaetae, with two on the underside, and the others on the sides. The bundles can contain one to 25 chaetae, and include muscles to pull them in and out of the body. This enables the worm to gain a grip on the soil or mud as it burrows into the substrate. When burrowing, the body moves peristaltically, alternately contracting and stretching to push itself forward.

A number of segments in the forward part of the body are modified by the presence of numerous secretory glands. Together, they form the clitellum, which is important in reproduction.

Internal anatomy

Most oligochaetes are detritus feeders, although some genera are predaceous, such as Agriodrilus and Phagodrilus. The digestive tract is essentially a tube running the length of the body, but has a powerful muscular pharynx immediately behind the mouth cavity. In many species, the pharynx simply helps the worm suck in food, but in many aquatic species, it can be turned inside out and placed over food like a suction cup before being pulled back in.

The remainder of the digestive tract may include a crop for storage of food, and a gizzard for grinding it up, although these are not present in all species. The oesophagus includes "calciferous glands" that maintain calcium balance by excreting indigestible calcium carbonate into the gut. A number of yellowish chloragogen cells surround the intestine and the dorsal blood vessel, forming a tissue that functions in a similar fashion to the vertebrate liver. Some of these cells also float freely in the body cavity, where they are referred to as "eleocytes".

Most oligochaetes have no gills or similar structures, and simply breathe through their moist skin. The few exceptions generally have simple, filamentous gills. Excretion is through small ducts known as metanephridia. Terrestrial oligochaetes secrete urea, but the aquatic forms typically secrete ammonia, which dissolves rapidly into the water.

The vascular system consists of two main vessels connected by lateral vessels in each segment. Blood is carried forward in the dorsal vessel (in the upper part of the body) and back through the ventral vessel (underneath), before passing into a sinus surrounding the intestine. Some of the smaller vessels are muscular, effectively forming hearts; from one to five pairs of such hearts is typical. The blood of oligochaetes contains haemoglobin in all but the smallest of species, which have no need of respiratory pigments.

The nervous system consists of two ventral nerve cords, which are usually fused into a single structure, and three or four pairs of smaller nerves per body segment. Only a few aquatic oligochaetes have eyes, and even then they are only simply ocelli. Nonetheless, their skin has several individual photoreceptors, allowing the worm to sense the presence of light, and burrow away from it. Oligochaetes can taste their surroundings using chemoreceptors located in tubercles across their body, and their skin is also supplied with numerous free nerve endings that presumably contribute to their sense of touch.

Families

• Randiellidae Erséus & Strehlow, 1986
• Naididae / Tubificidae Vejdovsky, 1884 (including Naidinae Ehrenberg, 1831)
• Narapidae Righi, 1983
• Opistocystidae Cernosvitov, 1936
• Dorydrilidae Cook, 1971
• Parvidrilidae Erséus, 1999
• Phreodrilidae Beddard, 1891
• Propappidae Coates, 1986
• Haplotaxidae Michaelsen, 1900
• Tiguassuidae Brinkhurst, 1988
• Lumbriculidae Vejdovsky, 1884
• Enchytraeidae Vejdovsky, 1879
• Moniligastridae Claus, 1880
• Alluroididae Michaelsen, 1900
• Syngenodrilidae Smith & Green, 1919
• Glossoscolecidae Michaelsen, 1900
• Tumakidae Righi, 1995
• Ailoscolecidae Bouché, 1969 (including Komarekionidae Gates, 1974)
• Sparganophilidae Michaelsen, 1918
• Microchaetidae Michaelsen, 1900
• Tritogeniidae Plisko, 2013
• Lumbricidae Claus, 1876 (including Diporodrilinae Bouché, 1970; Eiseniinae Omodeo, 1956; Spermophorodrilinae Omodeo & Rota, 1989; Postandrilinae Qiu & Bouché, 1998; Allolobophorinae Kvavadze, 2000 and Helodrilinae Kvavadze, 2000)
• Kynotidae Brinkhurst & Jamieson, 1971
• Hormogastridae Michaelsen, 1900 (including Vignysinae Bouché, 1970 and Xaninae Diaz Cosin et al., 1989)
• Lutodrilidae McMahan, 1978
• Criodrilidae Vejdovsky, 1884 (including Biwadrilidae Brinkhurst & Jamieson, 1971)
• Almidae Duboscq, 1902
• Ocnerodrilidae Beddard, 1891 (including Malabariinae Gates, 1966)
• Acanthodrilidae Claus, 1880 (including Diplocardiinae Michaelsen, 1900)
• Octochaetidae Michaelsen, 1900 (including Benhamiinae Michaelsen, 1895/7)
• Exxidae Blakemore, 2000
• Megascolecidae Rosa, 1891 (including Pontodrilinae Vejdovsky, 1884; Plutellinae Vejdovsky, 1884 and Argilophilinae Fender & McKey-Fender, 1990)
• Eudrilidae Claus, 1880

References

Bibliography

• Blakemore, R. J. (2005). Whither Octochaetidae? – its family status reviewed. In: Advances in Earthworm Taxonomy II. Eds. A. A. & V. V. Pop. Proceedings IOTM2, Cluj University Press. Romania. Pp. 63–84. http://www.oligochaeta.org/ITOM2/IOTM2.htm.
• Blakemore, R. J. (2006). Revised Key to Earthworm Families (Ch. 9). In: A Series of Searchable Texts on Earthworm Biodiversity, Ecology and Systematics from Various Regions of the World – 2nd Edition (2006). Eds.: N. Kaneko & M. T. Ito. COE Soil Ecology Research Group, Yokohama National University, Japan. CD-ROM Publication. Website: http://bio-eco.eis.ynu.ac.jp/eng/database/earthworm/.
• Erséus, C.; Källersjö, M. (2003). "18S rDNA phylogeny of basal groups of Clitellata (Annelida)". Zoologica Scripta 33 (2): 187–196. doi:10.1111/j.1463-6409.2004.00146.x. 
• Michaelsen, W. (1900). Das Tierreich 10: Vermes, Oligochaeta. Friedländer & Sohn, Berlin. Pp. xxix+575, figs. 1-13. Online here: http://mail2web.com/cgi-bin/redir.asp?lid=0&newsite=https://archive.org/details/oligochaeta10mich.
• Plisko, J.D. (2013). A new family Tritogeniidae for the genera Tritogenia and Michalakus, earlier accredited to the composite Microchaetidae (Annelida: Oligochaeta). African Invertebrates 54 (1): 69–92.[2]
• Siddall, M. E., Apakupakul, K, Burreson, E. M., Coates, K. A., Erséus, C, Gelder, S. R., Källersjö, M, & Trapido-Rosenthal, H. (2001). Validating Livanow's Hypothesis: Molecular Data Agree that Leeches, Branchiobdellidans and Acanthobdella peledina form a Monophyletic Group of Oligochaetes. Molecular Phylogenetics and Evolution, 21: 346-351. http://research.amnh.org/~siddall/pub/livanow.pdf.
• Stephenson, J. (1930). The Oligochaeta. Clarendon Press, Oxford. Pp. 978.

External links

• Media related to Oligochaeta at Wikimedia Commons

English Journal

• Reaction of oligoglia to spinal cord injury in rats and transplantation of human olfactory ensheathing cells.

• Masgutova GA1, Savchenko EA, Viktorov IV, Masgutov RF, Chelyshev YA.Author information 1Department of Histology, Cytology, and Embryology, Kazan State Medical University, Russia.AbstractIn experiments on rats with lateral TVIII hemisection of the spinal cord and transplantation of ensheating olfactory cells, we studied structural changes at the lesion site and adjacent rostral and dorsal regions of the spinal cord. The state of oligodendrocytes and myelin fibers and motor function in experimental animal were analyzed. Open field testing (BBB test) showed that motor functions steadily increased (by 13% on average) within the interval from day 21 to day 53 after transplantation. Histological examination showed that groups of transplanted cells carrying human nuclear marker (HNu(+)cells) were still present at the lesion site 30 days after surgery. Some of these cells migrated in the rostral and caudal directions from the injection site to a distance up to 6 mm. At the initial period after hemisection, the number of oligodendrocytes (O4(+)-cells) in the immediate vicinity to the lesion site decreased 2-fold, but no significant changes in the number of neurons were found in the rostral and dorsal fragments of the spinal cord compared to the corresponding parameter in controls. Sixty days after transplantation, the cross-section area in the rostral part of the spinal cord at a distance of 3 mm from damage site increased by 15.3% compared to the control. The number of O4(+)-cells at the lesion site and in adjacent rostral and caudal parts of the spinal cord by 22.8% surpassed that in the control group. The number of remyelinated axons also increased. These findings suggest that the absence of pronounced structural changes in the rostral and caudal parts of the spinal cord compared to lesion site at early stages after damage and cell transplantation. At the same time, pronounced activation of oligodendrocytes in this region suggests their involvement together with Schwann cells into remyelination of regenerating axons, which can serve as a factor of partial restoration of motor functions after spinal cord injury.
• Bulletin of experimental biology and medicine.Bull Exp Biol Med.2010 Jul;149(1):135-9.
• In experiments on rats with lateral TVIII hemisection of the spinal cord and transplantation of ensheating olfactory cells, we studied structural changes at the lesion site and adjacent rostral and dorsal regions of the spinal cord. The state of oligodendrocytes and myelin fibers and motor function
• PMID 21113476

• Small molecule peptidomimetic ligands of neurotrophin receptors, identifying binding sites, activation sites and regulatory sites.

• Saragovi HU1, Zaccaro MC.Author information 1Department of Pharmacology, McGill University, 3655 Drummond Street #1320, Montréal, Quebec, Canada H3G 1Y6. Uri@pharma.mcgill.caAbstractNeurotrophins (NTFs) are a family of polypeptide growth factors that control the apoptotic death or survival, growth, and differentiation of neurons. NTFs also regulate several other cell populations such as lymphoid, epithelial, oligoglia, and mast cells. Disregulation of the NTFs or their receptors plays a key role (etiological or upstream) in certain human pathologies. Hyperactivity may lead to inflammatory pain, or some forms of cancer by autocrine/paracrine growth. Loss of activity may lead to neurodegeneration, neuropathic pain, or some forms of cancer by absence of differentiation. Consequently the NTFs and their receptors are important therapeutic targets, and pharmacological modulation may have applications ranging from treatment of chronic or acute neurodegeneration, some forms of cancer, and chronic pain (with agonists); and some forms of cancer or acute pain (with antagonists).
• Current pharmaceutical design.Curr Pharm Des.2002;8(24):2201-16.
• Neurotrophins (NTFs) are a family of polypeptide growth factors that control the apoptotic death or survival, growth, and differentiation of neurons. NTFs also regulate several other cell populations such as lymphoid, epithelial, oligoglia, and mast cells. Disregulation of the NTFs or their receptor
• PMID 12369863

• Pelizaeus-Merzbacher disease. The Löwenberg-Hill type.

• Bruyn GW, Weenink HR, Bots GT, Teepen JL, van Wolferen WJ.AbstractThe clinical and neuropathological findings are reported of two sibs with adult type PMD. Clinical features deviating from the usual pattern included: no psychosis, no measurable dementia, no dwarfism, no microcephaly, no (marked) involuntary movements, but conspicuous generalised muscle atrophy and denervation, impairment of vital and gnostic sensation, thoracolumbar vertebral anomalies, and aplasia of os coccygis. Neuropathological findings were as usual, with additional unusual features: pinhead-size areas of acute myelin-abbau products, involvement of grey in addition to white matter, and upon ultrastructure, the new finding of intra-oligodendroglial fingerprint bodies, both in neuronal satellite and in white matter oligoglia, but not in astrocytes, ganglion cells, or pericytes. This excludes the origin of the stored material in the lysosomes as to derive exclusively from demyelination and would possibly imply PMD to be an oligodendroglial lysosomal storage disease.
• Acta neuropathologica.Acta Neuropathol.1985;67(3-4):177-89.
• The clinical and neuropathological findings are reported of two sibs with adult type PMD. Clinical features deviating from the usual pattern included: no psychosis, no measurable dementia, no dwarfism, no microcephaly, no (marked) involuntary movements, but conspicuous generalised muscle atrophy and
• PMID 4050332

Related Links

• oligoglia是什么意思_oligoglia在线翻译_oligoglia什么意思 ...

oligoglia是什么意思 oligoglia在线翻译 oligoglia什么意思 oligoglia的意思 oligoglia的翻译 oligoglia的解释 oligoglia的发音 oligoglia的 ... oligoglia是什么意思,oligoglia在线翻译,oligoglia什么意思,oligoglia的意思,oligoglia的翻译,oligoglia的 ...

• oligoglia

ol·i·gog·lia (ol″ĭ gogґle ə) oligodendroglia ... Look at other dictionaries: олигоглия — (oligoglia; олиго + (нейро)гли ) см. Олигодендроглия … Большой медицинский словарь

Related Pictures

---

★リンクテーブル★

リンク元	「乏突起膠細胞」「オリゴグリア」

「乏突起膠細胞」

　　[★]

英

oligodendrocyte

同

乏突起膠細胞、稀突起膠細胞、希突起膠細胞、希突起神経膠、希突起グリア、寡突起神経間質、オリゴデンドロサイト、オリゴデンドログリア oligodendroglia、オリゴグリア oligoglia

関

[[]]

[show details]

希突起膠細胞 : 約 64,300 件
乏突起膠細胞 : 約 51,800 件
稀突起膠細胞 : 約 22,700 件

髄鞘を形成する細胞

		ミエリン鞘 髄鞘	シュワン鞘
有髄神経	中枢神経	○(シュワン細胞)
	末梢神経	○(希突起膠細胞)	○
無髄神経		×

臨床関連

• 乏突起膠腫

「オリゴグリア」

　　[★]

英

oligoglia

関

乏突起膠細胞