TAPEWORMS: Taenia solium & Taenia saginata
-Lacanilao, Alyssa Gale C.
-Lanuza, Jo Ann
The pork tapeworm has several different habitats depending on the stage in its life cycle. * The preadult tapeworm and adult tapeworm can be found in the small intestine of a human host. * The proglottid segments full of eggs are found in the host feces, and in the external environment where the feces are released. Temperature is known to effect egg survival. If the habitat is colder than 10 degrees Celsius or above room temperature, the eggs can easily perish. * The oncosphere, this stage takes place inside the pig intermediate host. The habitat of the oncosphere is the gut and tissue of the pig host and continues its life stage in the muscle and brain of the pig in the cysticercus stage. * The cysticercus form is also capable of surviving in a human host, living in the muscles and the brain.
Other Habitat Features
The morphology of the adult pork tapeworm is divided into three parts: * Scolex - is the head of the tapeworm, positioned at the anterior end of the organism.
- acts as an attachment device with four suckers, hooks and rostellum
- used to attach itself to the intestine of the host
* Neck- is an elongated region between the scolex and the stroblia. * Stroblia- contains the bulk of the systems of the tapeworm * has an average length of 2-3 m
* It consists of multiple segments called proglottids
As a monoecious species, every single proglottid contains both the male and female reproductive systems. The proglottids mature sexually as they progress in the posterior direction of the strobila The pork tapeworm does not have a digestive system, but is composed of the following systems: * Tegument
Taenia solium egg's
* have a fragile outer shell that can be shed when the egg exits the host's body, leaving the oncosphere larva exposed to the external environment. The oncosphere larva
* is 30 um in diameter
* also called the hexacanth larva since it has six hooks. * The larva is a solid mass of cells and surrounded by a protective cover called the embryophore. * This cover protects the oncosphere from harsh conditions when the larva is exposed to the environment. * The oncosphere develops into the cysticercus form, converting from a solid larva to a vesicle with an opalescent fluid. * In the cysticercus form the scolex is discernible, but is invaginated at this stage. * The larva has an outer and inner layer and in between these layers the first signs of organ system differentiation is seen.
2 to 10 m
6.56 to 32.81 ft
Taenia solium has six stages in its life cycle:
* preadult tapeworm
* adult tapeworm
* postoncospheral form
* and cysticercus
* The preadult and adult tapeworm occur in the definitive host, the human. These two stages can only occur when the definitive host consumes pork infected by the cysticercus stage because the adult must mature in the definitive host's intestine.
* The adult tapeworm is the reproductive stage in the life cycle and a single sexually mature proglottid contains an average of 40,000 eggs.
* These eggs are shed through the host's feces and then consumed by a pig, the intermediate host. The pig ingests the human fecal matter under poor sanitation conditions. The egg sheds its outer shell and becomes the oncosphere larva. The egg may also shed its outer shell while being expelled from the definitive host. In this situation, it is the oncosphere that is consumed by the pig.
* The larva enters the intermediate host's circulation system and is carried to...
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