Important nematode parasites of humans Essay

Important nematode parasites of humans
Nematode is also called roundworm. The majority of the species live in the life of the non- parasitic in the soil and ocean. Similarly, the presences of parasitic nematodes are also known. The study of nematodes which leads to damage to the crop in plant-parasitic is called nematology. The study of nematodes which are parasitic to human and vertebrates is called parasitology.
General Characteristics
Body is in the form of elongated filaments.
It is essentially colorless and transparent.
Do not have a somite structure.
With a false body cavity.
Although sexual reproduction in dioecious is primarily, but there are some species that reproduce in asexually reproduction.
Huge number of individuals in the soil , and is also said to have accounted for 15% of the biomass on Earth.
Common parasitic nematodes of human
Examples-
Hookworm
Pinworm
Intestinal roundworm
Trichina worm
Whipworm
Intestinal roundworm
Also called roundworms and scientific name is ascaris lumbricoides. Roundworm is mainly parasitic of the small intestine, of many mammals especially in humans. It is most common parasite in the world about one billion people are infected.
Characteristics
No visual sensory organs.
Reproductive system is develop, which occupy most of the insect body. Mature females lay eggs from 10 million to 25 million per day.
There is a mouth and anus to the tip of the body.
It is dioecious. Male length is 15~30cm and female length is 20~35cm. Male is larger than the female.
Life cycle
Up to 25 million of roundworm eggs are laid by one female but these are not to hatch. Discharged eggs, it becomes embryo and then infective juveniles in about one month if temperature is about 15 . Infecting usually occurs when eggs are ingested with uncooked vegetables or when children put soiled fingers or toys in their mouth. In intestine, it go out into the body cavity by eating the intestinal wall then it invades the blood vessels, and reaching the lungs via the liver. In this time, it grow about 1mm in length.. Period is life is two to four years.
Because it has such a complex life form, so it has a name of "roundworm". Reason to follow such a complex route of life form is not clear.
Whipworm -
Scientific name is of whipworm is trichuris trichiura. Whipworm is a nematode belonging to the genus Trichuris.
Characteristics
Size of female adults is 35 ~ 50 mm in lengths, and 1.7mm in width. Size of male adults is 30 ~ 45 mm in lengths, and 1.3mm in width.
Egg have eggshell and its color is dark brown and there is a colorless plug on both side of an egg.
Adult wormhave a very thin whip like structure at upper part of its body.
And parasitic and allowed to shallowly buried in the human cecum mucosa
Its host is only human, causing trichuriasis
Life cycle