parasitic worm

Examples of parasitic worm in the following topics:

• Distribution and Importance of Parasitic Worms

  • Parasitic worms, distributed worldwide, are hypothesized to have importance in immune system regulation.
  • Parasitic worms, often the result of horrible illness and disease, appear to have medicinal properties as well.
  • The importance of parasitic worms has come to light in regards to treating various diseases which may benefit from their presence.
  • It is argued that humans have evolved with parasitic worms and there is a mutualistic relationship which mandates the need for parasitic worms to contribute to a healthy immune system.
  • The study showed that parasitic worm infection results in an increase in eosinophils, thus, promoting control of glucose maintenance .

• Helminths

  • Parasitic worms, often referred to as helminths, are a division of eukaryotic parasites.
  • Parasitic worms, often referred to as helminths, are a division of eukaryotic parasites.
  • Populations in the developing world are at particular risk for infestation with parasitic worms.
  • As humans have evolved with parasitic worms, proponents argue that they are needed for a healthy immune system.
  • List the four groups of parasitic worms (helminths), routes of transmission and risk factors

• Classification and Identification of Helminths

  • Helminths, or parasitic worms, are eukaryotic parasites characterized by their ability to feed and live on living hosts.
  • Helminths and multicellular eukaryotes, can either be free-living or parasitic.
  • These parasites live in and feed on hosts which allow them to obtain nourishment while disrupting the hosts' nutrient absorption.
  • Parasitic worms are commonly found within the intestine and thus, are called intestinal parasites.

• Characteristics of Helminths

  • Helminths are parasitic worms that live and feed on living hosts to receive nourishment and protection which results in illness of the host.
  • Parasitic worms that inhabit the intestinal tract (blood, tissue and organs) of humans are referred to as helminths.
  • Helminths share numerous characteristics that contribute to their parasitic quality including the presence of attachment organs.
  • Intestinal helminths are commonly transmitted through fecally contaminated food and water and these parasites include Ascaris lumbricoides, Trichuris trichiura (whipworm), and Enterobius vermicularis (pin worm).
  • The eggs will mature and hatch in the soil and the immature worms (larvae) will penetrate the skin of humans if contact is made.

• Antiprotozoan and Antihelminthic Drugs

  • Two major classes of parasitic organisms include protozoa and helminths.
  • Helminths are parasitic worms and are divided into three major groups including: flatworms (platyhelminths); thorny-headed worms (acanthocephalins); and roundworms (nematodes and hookworms).
  • This parasite is injected into humans via mosquitoes.
  • Helminths are characterized as various types of parasitic worms, which are effectively targeted by promoting expulsion from the body.
  • Parasitic helminths worms include: tapeworms, flukes, leeches and hookworms.

• Symbiosis

  • In this relationship the parasite benefits, but the organism being fed upon, the host, is harmed.
  • The parasite, however, is unlikely to kill the host.
  • This diagram shows the life cycle of a pork tapeworm (Taenia solium), a human worm parasite.
  • When they hatch, the worms travel through the wall of the intestine and begin to grow.
  • Here, the parasite will absorb the nutrition from the host and continue to grow.

• Phylum Nematoda

  • Nematodes are parasitic and free-living worms that are able to shed their external cuticle in order to grow.
  • Furthermore, the nematodes, or roundworms, possess a pseudocoelom and have both free-living and parasitic forms.
  • Phylum Nematoda includes more than 28,000 species with an estimated 16,000 being parasitic in nature.
  • The overall morphology of these worms is cylindrical, while the head is radially symmetrical .
  • All nerve cords fuse at the anterior end, around the pharynx, to form head ganglia, or the "brain" of the worm (taking the form of a ring around the pharynx), as well as at the posterior end to form the tail ganglia.

• Phylum Platyhelminthes

  • The Catenulida, or "chain worms" is a small clade of just over 100 species.
  • These worms typically reproduce asexually by budding.
  • Many flatworms are parasitic, including important parasites of humans.
  • Parasitic forms feed on the tissues of their hosts.
  • This necessarily limits the thickness of the body in these organisms, constraining them to be "flat" worms.

• Nematodes

  • Analysis of parasitic nematodes reveals the presence of specific body structures which promote parasitic behaviors such as ridges, rings or bristles that allow for attachment.
  • Ascariasis is a disease that is caused by the parasitic roundworm Ascaris lumbricoides.
  • For a second time, the larvae enter into the intestine and mature into adult worms .
  • The presence of the worms within the intestine may also result in malabsorption or intestinal blockage.
  • Shortly after mating, the male worms die and are passed out via the feces.

• Swimmer's Itch

  • There are numerous types of flatworm parasites within the family Schistosomatidae that can cause swimmer's itch.
  • The life cycle of these parasites is characterized by their use of both freshwater snails and vertebrates as hosts.
  • During the life stage of these parasites, the larvae of the parasite, cercaria, exit the water snails and can accidentally come into contact with the skin of a swimmer.
  • For completion of the cycle, adult worms will form in the blood vessels and produce eggs which are passed in the feces.
  • Outline the general life cycle of the Schistosomatidae parasite that causes schistosome cercarial dermatitis