nematodes: roundworms. what are nematodes? roundworms pseudocoelom complete digestive tract ...
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NEMATODES: ROUNDWORMS
What are Nematodes?
Roundworms Pseudocoelom Complete Digestive
Tract Cuticle 25,000 identified
but it is estimated that there are really close to 500,000 species
Some are parasitic
Inside a Nematode
Complete Digestive Tract
A continuous tube that goes from the mouth to the anus
Fluids absorbed from the digestive tract are spread through rest of body by pseudocoelom
The body cavity is in direct contact with the digestive tract
Hydroskeleton: soft bodied, fluid filled cavity
Contractions of longitudinal muscles allows for its muscle pattern
Digestive Tract Pseudocoelom
ANATOMY
Nematodes are often found in rotting living matter. Some are decomposers in soil and are found in the bottom of lakes and oceans. They may additionally be parasites that live in the tissue of plants and in the body tissue and fluid of animals.
Where are they found?
Carrot infested with the root knot nematode
Basics
Range from 1mm to 1m in size
Bilateral symmetry 3 tissue layer
construction of the body
Cuticle: tough nonliving material that prevents drying out of the body
Parasitism
Some nematodes are predators to eat other microscopic animals. They also invade many the tissue of some plants and animals. The cuticle protects the nematode against the host’s digestive system.
Dog heartworms are an example of a parasitic nematode.
Trichinella Spiralis
Humans can be a host
Enters the body through consumption of undercooked meat
The Cycle
Nematodes
Hookworms
Grab onto intestinal walls
Suck blood of host
Can cause anemia
Affects millions of people world wide as well as animals
Sources
http://www.ars-grin.gov/ars/SoAtlantic/fp/stpp/burelle/nematode.jpg
http://www.gettyimages.com/Search/Search.aspx?contractUrl=2&language=en-US&family=creative&p=nematodes&assetType=film&src=quick
http://edis.ifas.ufl.edu/LyraEDISServlet?command=getScreenImage&oid=13304504
http://www.apsnet.org/education/introplantpath/PathogenGroups/intronematodes/images/fig07.jpg
Sources (cont.)
http://www.phsource.us/images/Helminths/Trichinella_spiralis.jpg
http://www.greatlakesbcrescue.org/HealthNTraining/heartworms.JPG
http://pet-care-junction.com/blog/wp-content/uploads/2008/05/hookworms-in-pets.gif
Biology: Concepts and Connections (textbook)