Nematoda overview
Nematods are commonly called roundworms, because that is exactly what they look like. They are a bilaterally symmetrical organism that is surrounded by a strong layer called a cuticle (skeleton). It is used as a support and leverage point for movement. They move with the contraction of the longitudinal muscles. The animal moves by thrashing back and forth, where no cilia or flagellae are at work. Because there are no flame cells, nematods excrete their wastes by canals/specialized cells. Fertilization takes place directly, when the male uses special copulatory spines. There are many nematods found places such as apples and mud where numbers can total hundreds and thousands of species. They are found in almost every habitat on earth, including the most unexpected places as well. Nematods play very important roles in decomposition on earth. They are also predators for microorganisms on earth. Nematods also have an affect on humans (dangerous) and include hookworms, pinworms, and roundworms.
HOOKWORMS
A hookworm is a nematode that is parasitic. It usually lives in the small intestine of its host (commonly dogs, pigs etc.). The two species of hookworms that infect humans are Ancylostoma duodenale and Necator americanus. Hookworms affect more than 600 million people in the world, and there are the most cases in more rural areas. Hookworms tend to be very small, as the chance of anemia goes higher. They suck blood from the host, and damage the mucosa. Hookworms are the leading cause of maternal and child morbidity in the tropics and subtropics. There may be intellectual, cognitive, and growth retardation, prematurity, and low birth weight. When the mothers have offspring, these symptoms may occur. The anemia caused by the hookworm can have a significant affect on an individual. You can prevent getting a hookworm by not walking barefoot in infected areas, not using human excrement/other foreign objects as fertilizer, and not to defecate in unknown areas. They have no circulatory or respiratorysystems, so they use diffusion to breathe and for circulation of substances around their body.
Hookworm epidermis secretes a layered cuticle made of keratin that protects the body from drying out, from digestive juices, or from other harsh environments. Because it is inelastic and does not allow the volume of the hookworm to increase, the worm has to molt and form new cuticles. The larval stages are designated L1 to the L5 (adult).
Hookworms require a moist, fairly cool environment to survive usually within 17-30 oC.
citation: http://www.newworldencyclopedia.org/entry/Hookworm
Hookworm epidermis secretes a layered cuticle made of keratin that protects the body from drying out, from digestive juices, or from other harsh environments. Because it is inelastic and does not allow the volume of the hookworm to increase, the worm has to molt and form new cuticles. The larval stages are designated L1 to the L5 (adult).
Hookworms require a moist, fairly cool environment to survive usually within 17-30 oC.
citation: http://www.newworldencyclopedia.org/entry/Hookworm
PINWORMS
Pinworms are small parasites that reside in the colon and the rectum. When you swallow pinworm eggs, you are now infected with pinworms. The eggs hatch inside the intestines and the female pinworms lay eggs on nearby skin. They spread really easy and they can spread eggs to other people through hands or through clothing. Pinworms are most commonly found in children. There are few to no symptoms in having pinworms, but there may be a slight itch in the lower area. You can collect the eggs off of your skin by using tape, and smaller infections do not require treatment. You can help to prevent becoming infected by taking daily showers, washing clothes/sheets often, avoid scratching your anal area, and avoid nail biting. There is no formal respiratory system, but they breathe through their body walls.
WHIPWORMS
Whipworm infection is caused by the roundworm, Trichuris trichiura. It is most common in children, and they may become infected if they swallow contaminated soil containing whipworm eggs. When the eggs hatch inside the body, it stays in the large intestine. They are dispersed throughout the world, and mostly found in countries with warmer climates. Some causes could have been due to contaminated vegetables that come from the ground. The symptoms of a whipworm can include bloody diarrhea, anemia, and fecal incontinence. You can see if you have a whipworm by taking a stool ova and parasites exam. To treat whipworms, you have to take Mebendazole for 3 days by mouth and sometimes Ivermection. To prevent whipworms, there has to be improved bathrooms that are cleaner and more sanitary. You can also wash your hands and make sure the food is prepared correctly. The intestinal parasites absorb oxygen through their skin. The insect larva that live in ponds transport through their tails.
citation: http://answers.yahoo.com/question/index?qid=20081202151553AAT4UB7
citation: http://answers.yahoo.com/question/index?qid=20081202151553AAT4UB7