Timing of treatments is determined by local epidemiologic factors and additional treatments by unusually suitable conditions for parasite multiplication. The ovary is in the form of a ramified tube situated in the right anterior region and above the middle line of the body, in front of the testes. The two vasa deferentia unite and form a median coiled and dilated vesicula seminalis. Several other lymnaeid snails may be naturally or experimentally infected with F. It also helps in the absorption of nutrients particularly glucose from the host.
A curious factor in Fasciola is that its excretory canals normally contain an abundance of fat droplets. Infection to New Primary Host Sheep. It is also widespread in some areas in Europe and Asia. It demarcates the boundary between cuticle and muscle layers. In the ruminant host, the young flukes excyst and remain in the small intestine for 3—6 wk before migrating forward through the reticulum to the rumen. The lumen of the oviduct at the region yolk is termed ootype.
Reserve food in the form of glycogen and fats is stored in the parenchyma. Also tegument bears spinules which in turn help in locomotion, protection and in anchorage of the parasite body in the bile ducts of the host. Mesoderm constitutes uninucleate and binucleate cells with syncytial network filled with cytoplasm. The metacercaria excysts in the duodenum and the young fluke, on escape, may reach the liver through bile ducts or hepatic portal vein, and grows rapidly to reach the adult stage. The fertilized egg is surrounded by yolk cells and is developed into shelled egg or capsule. This main canal branches into four sections within the dorsal and ventral regions of the body. The excretory system consists of a complicated arrangement of branched tubules so as to facilitate the collection of various metabolic excretory wastes of the body.
On the ventral surface, a little behind the head lobe, is situated a much bigger sucker called the ventral or posterior sucker also known as acetabulum. Release of Fertilized Eggs from Primary Hosts sheep Body: After being released from the ovary, the eggs are fertilized either in the oviduct or within the ootype. They come out of the sporocyst by rupturing the wall of the sporocyst. In fact, on one hand adult fluke exhibits certain adaptive features and on the other a number of adaptive features may also be accounted from the various stages of its life history. An is the diagnostic test of choice. This condition is known as liver rot.
Since it lives in an environment which is devoid of oxygen, hence, anaerobic mode of respiration occurs; respiratory organs are completely wanting. Monosaccharides can directly diffuse through the body surface. Nervous System and Sense Organs of Fasciola : a. Female organs consist of single and branched ovary, a convoluted oviduct, shell gland, a uterus, which leads to the genital pore. The capillary ducts from a few protonephridia open into narrow collecting tubule. The adult can then produce up to 25,000 eggs per per day.
Outside the body, the flukes live in snails, the intermediary hosts. In areas where heavy infections are expected, sheep may require treatment in September or October, January or February, and again in April or May to reduce both the chances of acute or chronic infections and the output of fluke eggs for development of future disease. It opens in the genital atrium near the base of the cirrus. After three to six weeks, depending upon the temperature, the egg shell opens at the operculum and the miracidium larva emerges. Fasciola gigantica is similar in shape to Fasciola hepatica but is longer 75 mm , with less clearly defined shoulders, and is 12 mm wide. Absence of sense organ is due to parasitic mode of life. Chronic fasciolosis can be seen in all seasons but manifests primarily in late fall and winter.
It attacks sheep and causes liver rot disease in them. The somatic cell divides and forms the ectoderm of the larva. In humans, the time taken for F. This parasite infects the muscle tissues of pigs and is usually passed to humans by improperly cooked pork products. Nerve cords are connected by transverse commissures and they give out many small branches, some of which form plexuses. It is of immense parasitological and pathological importance as it is the causative organism of Fascioliasis.
The glands, nerve tissue, apical papilla and eye spots of miracidium disappear. Liquid food is sucked up by the muscular pharynx and is pumped into the intestine through the oesophagus. Infestations result in high worm burdens and intestinal blockages. So, the adaptive features of Fasciola hepatica can be discussed in the following two headings: A. In chronic cases, cirrhosis develops. Liver damage and jaundice accompany the disease. Musculature Fasciola has three muscle layers namely circular muscle layer, longitudinal muscle layer and diagonal muscle layer.
They move actively by the help of their tail and forces their way out of the snails body. Once in freshwater, the eggs become , allowing them to hatch as , which then find a suitable intermediate snail host of the family. Liver fluke feeds on tissue elements and exudates including bile, blood, and lymph. Alimentary canal is well developed and consists of mouth, pharynx and a bifid intestine. Although molluscicides can be used to reduce lymnaeid snail populations, those that are available all have disadvantages that restrict their use. Meaning of Fasciola Hepatica 2. The worms penetrate the human skin and pass from the blood to the lungs, and eventually to the digestive system.
In addition to mouth aperture, there are two permanent apertures on the body; one situated mid-ventrally in front of the ventral sucker is the common genital aperture or gonopore, and the other is situated at the posterior end of the body called the excretory pore. The flagella are enclosed in a funnel, shaped space, formed by the end of a capillary, coming from the excretory duct and flicker constantly like a flame. Each egg receives a fair amount of yolk from the yolk cells and vitelline secretions. It bears a circular ridge or collar near the anterior end, formed by the bulging of body wall. Since process of digestion does not occur, anus is absent and, hence, circulatory system is wanting because the various organs of alimentary canal intestine and its various branches distribute the already digested food substances to the different parts of its body.