L7

Fasciola hepatica ? Adult

? The adult Fasciola hepatica worm is flattened, leaf like shape, equipped with shoulders, somewhat oblong. Adult Fasciola hepatica measuring 3cm by 1cm in size, grayish in color. There are two suckers, oral sucker and ventral sucker, they located in cephalic zone. The intestine is branched, there are many branched testis, vitellaria situated in body laterals and the posterior end. The uterus is short and coiled filled with grayish eggs.
Life cycle Fasciola hepatica, the sheep liver fluke, causes disease primarily in sheep and other domestic animals in Latin America, Africa, Europe, and China. Humans are infected by eating watercress (or other aquatic plants) contaminated by larvae (metacercariae) that excyst in the duodenum, penetrate the gut wall, and reach the liver, where they mature into adults. Hermaphroditic adults in the bile ducts produce eggs (unembryonated operculated ovum) , which are excreted in the feces. The eggs hatch in fresh water, and miracidia enter the snails. Miracidia develop into cercariae, which then encyst on aquatic vegetation. Sheep and humans eat the plants, thus completing the life cycle.