Gourt > Health > Conditions and Diseases > Infectious Diseases > Parasitic > Nematodes
The nematodes or roundworms (Phylum Nematoda from Gr. nema, nematos "thread" + ode "like") are one of the most common phyla of animals, with over 20,000 different described species (over 15,000 are parasitic). They are ubiquitous in freshwater, marine, and terrestrial environments, where they often outnumber other animals in both individual and species counts, and are found in locations as diverse as Antarctica and oceanic trenches. Further, there are a great many parasitic forms, including pathogens in most plants and animals, humans included. Only the Arthropoda are more diverse.
The Nematodes were originally named Nematoidea by Rudolphi (1808). They were renamed Nematodes by Burmeister 1837 (as a family; Leuckart 1848 and von Siebold 1848 both promoted them to the rank of order), then Nematoda (Diesing 1861), though Nathan Cobb (1919) argued that they should be called Nemata or Nemates (and in English 'nemas' rather than 'nematodes'). After some confusion which saw the nematodes placed (often together with the horsehair worms, Nematomorpha) as a class or order in various groups such as Aschelminthes, Lankester (1877) definitively promoted them to the level of phylum.
Morphology
Nematodes are triploblastic protostomes with a complete digestive system. Roundworms have no circulatory or respiratory systems so they use diffusion to breathe and for circulation of substances around their body. They are thin and are round in cross section, though they are actually bilaterally symmetric. Nematodes are one of the simplest animal groups to have a complete digestive system, with a separate orifice for food intake and waste excretion, a pattern followed by all subsequent, more complex animals. The body cavity is a pseudocoel (persistent blastula), which lacks the muscles of coelomate animals used to force food down the digestive tract. Nematodes thus depend on internal/external pressures and body movement to move food through their digestive tracts. The mouth is often surrounded by various flaps or projections used in feeding and sensation. The portion of the body past the anus or cloaca is called the "tail." The epidermis secretes a layered cuticle made of keratin that protects the body from drying out, from digestive juices, or from other harsh environments, as well as in some forms sporting projections such as cilia that aid in locomotion. Although this cuticle allows movement and shape changes via a hydrostatic skeletal system, it is very inelastic so does not allow the volume of the worm to increase. Therefore, as the worm grows, it has to moult and form new cuticles. The cuticles don't allow volume to increase so as to keep hydrostatic pressure inside the organism very high. For this reason, the roundworms do not possess circular muscles (just longitudinal ones) as they're not required. This hydrostatic pressure is the reason the roundworms are round. More on [ Nematode ]
Food and Water Borne :: Conditions and Diseases
Zoonoses
Eighty percent of animals on Earth are nematodes: mostly microscopic worms. If the planet were vaporized, they would outline its surface.
sonomapinot (sonomapinot) Wed, 04 Nov 2009 02:41:08 -0000
Eighty percent of animals on Earth are nematodes: mostly microscopic worms. If the planet were vaporized, they would outline its surface.
Cynthia Kenyon paper in Cell Metabolism showing that glucose shortens lifespan of nematodes through DAF-16. http://bit.ly/3jjmHY
bstockwell (Brent Stockwell) Tue, 03 Nov 2009 19:48:25 -0000
Cynthia Kenyon paper in Cell Metabolism showing that glucose shortens lifespan of nematodes through DAF-16. http://bit.ly/3jjmHY
Are nematodes the answer to the obesity epidemic? http://tumblr.com/xbd3tze3v #quackery
lyall (Lyall) Tue, 03 Nov 2009 11:25:09 -0000
Are nematodes the answer to the obesity epidemic? http://tumblr.com/xbd3tze3v #quackery
@casenewsom That's a drug for intestinal nematodes... What does that have to do with anal itching?
bashmourad (bashar) Tue, 03 Nov 2009 00:17:55 -0000
@casenewsom That's a drug for intestinal nematodes... What does that have to do with anal itching?
Marine biology: 114-118. Take notes on Nematodes and Segmented Worms.
WLCAEnglish (Miss Hugo's Class) Mon, 02 Nov 2009 23:26:49 -0000
Marine biology: 114-118. Take notes on Nematodes and Segmented Worms.
Free workshop on garden invertebrates (insects, worms, slugs, nematodes, etc.) Thursday Nov. 12th 6:30 PM. Register with NBB: 882-0936 x225
ColumbiaSprings (Columbia Springs EEC) Mon, 02 Nov 2009 19:54:51 -0000
Free workshop on garden invertebrates (insects, worms, slugs, nematodes, etc.) Thursday Nov. 12th 6:30 PM. Register with NBB: 882-0936 x225
Angiostrongyliasis - CDC DPDx - Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment.
Anisakiasis - Humans are infected by consuming raw or undercooked fish. Features symptoms, effects on the body, and cause of the disease.
Anisakiasis - CDC DPDx - nematode Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment.
Anisakis simplex and related worms: Bad Bug Book - Features cause, symptoms, diagnosis, complications, associated foods, target populations, and outbreaks.
Meta Description: [ Provides basic facts about anisakis simplex and related
worms. ]
Ascariasis - Disease fact sheet from the World Health Organization, prepared for World Water Day 2001.
Meta Description: [ Disease fact sheet from the World Health Organization, prepared for World Water Day 2001 ]
Ascariasis: Kidshealth - Factsheet with signs and symptoms, treatment, and tips for prevention.
Meta Description: [ Ascariasis is an intestinal infection that occurs when the eggs of a parasitic roundworm are ingested. Read our article to learn more, including signs and symptoms, treatment, and tips for prevention. ]
Ascaris Infection - CDC Division of Parasitic Diseases - Includes factsheets on organism and the disease it causes, news releases, and reports.
Ascaris lumbricoides - Includes images, life cycle, and the pathology the nematode causes.
Ascaris lumbricoides and Trichuris trichiura: Bad Bug Book - Features cause, symptoms, diagnosis, complications, associated foods, target populations, and outbreaks.
Meta Description: [ Provides basic facts about ascaris lumbricoides and trichuris
trichiura ]
Baylisascaris Infection Fact Sheet - CDC Division of Parasitic Diseases - Includes factsheets on the raccoon roundworm and the disease it causes, news releases, and reports.
Meta Description: [ Resource Not Available ]
Baylisascaris procyonis: An Emerging Helminthic Zoonosis - Scientific and medical article on the raccoon roundworm and its effects on people.
Capillariasis - CDC DPDx - Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment.
Creeping Eruption: MedlinePlus Medical Encyclopedia - Features cause, risk factors, symptoms, tests, treatment, complications, and prevention.
Eustrongylides sp. : Bad Bug Book - Features cause, symptoms, diagnosis, complications, associated foods, target populations, and outbreaks.
Meta Description: [ Provides basic information on Acanthamoeba spp., Naegleria fowleri and other amobae ]
Gnathostomiasis - CDC DPDx - Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment. Human gnathostomiasis is due to migrating immature worms.
Guinea Worm Disease Facts - Factsheet with cause, geographic distribution, at risk poulation, symptoms, prevention, and treatment.
Guinea Worm Disease or Dracunculiasis - CDC Division of Parasitic Diseases - Includes factsheets on the organism and the disease it causes, news releases, and reports.
Guinea Worm or Dracunculiasis: WHO - Features disease information and status, control activities, and links.
Hookworm : MedlinePlus Medical Encyclopedia - Features cause, risk factors, symptoms, tests, treatment, complications, and prevention.
Hookworm Infection - CDC Division of Parasitic Diseases - Includes factsheets on the organism and the disease it causes, news releases, and reports.
Hookworms - Ancylostoma sp. and Necator sp. - Includes life cycle, images, and pathology.
MedlinePlus Medical Encyclopedia: Ascariasis - Features cause, risk factors, symptoms, tests, treatment, complications, and prevention.
Medmicro: Enteric Nematodes of Humans - Medical and scientific information on the organisms and the diseases they cause.
Parasitic Roundworm Diseases - Factsheets on nematodes that infect people.
Strongyloidiasis - CDC DPDx - Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment.
Toxocariasis Fact Sheet - CDC Division of Parasitic Diseases - Includes cause, symptoms, prevention, and treatment.
Toxocariasis: Kidshealth - Toxocara are common parasites of dogs and cats. When they infect humans, the illness is called toxocariasis or visceral larva migrans.
Meta Description: [ Toxocara are common parasites of dogs and cats. When they infect humans, the illness is called toxocariasis. ]
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Trichinella: Food Safety Research Information Office - Directory of factsheets, reports, press releases, and resources on the parasite and its effects.
Trichinosis - CDC Division of Parasitic Diseases - Includes factsheets on the organism and the disease it causes, news releases, and reports.
Trichinosis: MedlinePlus Medical Encyclopedia - Features cause, risk factors, symptoms, tests, treatment, complications, and prevention.
Trichuriasis - CDC DPDx - Factsheet with causal agents, life cycle, geographic distribution, laboratory diagnosis, and treatment.
What Is A Hookworm Infection or Ancylostomiasis? - Features images, cause, treatment, symptoms, and prevention.
WHO/OMS: Intestinal Nematodes - Factsheets and publications.
WHO: Water related diseases: Ascariasis - Factsheet with disease information, distribution, scope of the problem, and prevention.
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