Description
T. saginata is normally 4 m to 10 m in length, but can become very large, over 12 m long in some situations. The body is whitish in colour, divided into the anterior scolex, followed by a short neck and a highly extended body proper called the strobila. Unlike other tapeworms, the scolex does not have a rostellum or scolex armature. It is composed of four powerful suckers. The strobila is composed a series of ribbon-like segments called proglottids. The segments are made up of mature and gravid proglottids. T. saginata is the largest of genus Taenia, consisting between 1000 to 2000 proglottids, and can also have a lifespan of 25 years in a host's intestine. The mature proglottid contains the uterus (unbranched), ovary, genital pore, testes, and vitelline gland. It does not have a digestive system, mouth, anus, or digestive tract. It is also an acoelomate, meaning it does not have a body cavity. In the gravid proglottid, the uterus is branched and filled with eggs. The gravid segments detach and are passed in the feces. Each of these segments can act as a worm. When they dry up, the proglottid ruptures, and the eggs are released. The egg can only infect cattle, the intermediate host. Inside the cow's duodenum, the oncosphere hatches with the help of the gastric and intestinal secretions, and migrates through the blood to the muscle. There it develops into infective cysticercoid cysticerci.
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