In this article we will discuss about the external morphology of roundworm or Ascaris. Ascaris resembles an ordinary earthworm and is the largest intestinal nematode parasitising man. It is milk-white in colour but presents a reddish-yellow shade. Body is elongated, cylindrical, and gradually tapering at both ends. The females are usually 20-25 cm in length and 5 mm in diameter [...]
Sporocyst Larva: It looks like an elongated sac, about 0.7 mm long. Its body-wall retains all the layers of body wall of Miracidium except the ciliated ectoderm. During metamorphosis into Sporocyst, the outer coat of ciliated cells is thrown off, the pigment cells of the eye-spot separate from one another and loose their crescentic form and the organism becomes a [...]
Transmission of E. histolytica from man to man occurs through its encysted stage and infection is effected through the ingestion of these cysts in food or drinks. It is to be noted that mature quadrinucleate cysts are the infective forms of this parasite. The contamination of food and drinks is occurred by: i. Faecal contamination of drinking water, vegetables and [...]