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==Feeding and Digestion==

==Feeding and Digestion==

The pharynx is situated at the anterior end of the nematode and is used in feeding, often being embedded into the epidermis or blood vessels of the worms predilection site. The pharynx may be specialized depending on the predeliction site and food type that the nematode requires, many blood feeders have teeth or plates used for attachment. The pharynx has a radial muscle that is used in pumping food into the intestines. The food enters the buccal capsule the size and shape of which is characteristic in some species of nematode. Due to the high pressure levels in the nematode body cavity there is a one way valve between the oesophagus and intestines and food is pushed through this by peristaltic action of radial oesophageal muscles.

The pharynx is situated at the anterior end of the nematode and is used in feeding, often being embedded into the epidermis or blood vessels of the worms predilection site. There are a number of different mechanisms by which nematodes feed. Some nematodes will feed on the ingesta of the host or its secretions, whilst others will suck a 'plug' of mucosa into their buccal capsules, generating an ulcer. One of the most damaging ways in which nematodes feed is by burying deep into the mucosa and feeding directly on the hosts blood. The pharynx may be specialized depending on the predeliction site and food type that the nematode requires, many blood feeders have teeth or plates used for attachment. The pharynx has a radial muscle that is used in pumping food into the intestines. The food enters the buccal capsule the size and shape of which is characteristic in some species of nematode. Due to the high pressure levels in the nematode body cavity there is a one way valve between the oesophagus and intestines and food is pushed through this by peristaltic action of radial oesophageal muscles.

The intestines of nematodes are simple tubes, only a single cell thick. The number of cells can range from 10's to one million and can be used as an identifying feature in some species. The cells are lined with microvilli, similarly to those in the mammalian gut, which are use to provide surface area for the absorption of nutrients. Lipid globules are also stored within the intestinal lumen and can occupy up to 50% of its volume. Digestion occurs rapidly and faeces is expelled under pressure from the posterior of the nematode.  

The intestines of nematodes are simple tubes, only a single cell thick. The number of cells can range from 10's to one million and can be used as an identifying feature in some species. The cells are lined with microvilli, similarly to those in the mammalian gut, which are use to provide surface area for the absorption of nutrients. Lipid globules are also stored within the intestinal lumen and can occupy up to 50% of its volume. Digestion occurs rapidly and faeces is expelled under pressure from the posterior of the nematode.  

*http://entomology.ucdavis.edu/courses/ent156/securedocs/lectures/ENT156T3.pdf

[[Image:Mononchidae eating a Mononchidae.jpg|thumb|right|150px|Mononchidae eating a Mononchidae - Wikimedia Commons]]

*Some swallow ingesta and/or host secretions.

 

[[Category:Nematodes|A]]

[[Category:Nematodes|A]]

[[Category:To_Do_-_Parasites]]

[[Category:To_Do_-_Parasites]]

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