What is the larva of a tapeworm called?
The tapeworm forms what is called a cysticercus, a larva that consists of a fluid-filled sac nestled in the tissue of the host. According to the Centers for Disease Control and Prevention (CDC), cysticercosis is caused by unintentionally eating fecal matter from a person infected with intestinal tapeworms.
What is the attachment structure of the tapeworm called?
Tapeworms (cestodes) are exclusively internal necrotrophs that usually attach inside the gut of vertebrates by means of a specialized structure, the scolex. The scolex may contain exclusively suckers or a combination of suckers and other structures enabling a firm grasp of the host tissue.
What is cysticercus larva?
Cysticercus (pl. cysticerci) is a scientific name given to the young tapeworms (larvae) belonging to the genus Taenia. It is a small, sac-like vesicle resembling a bladder; hence, it is also known as bladder worm.
What is the scolex of a tapeworm?
The scolex at the anterior end of the cestode is a specialized body segment (or proglottid), which anchors the parasite to its host. The scolex is usually covered with hooks or suckers and is used by helminth taxonomists as a key characteristic for identifying species of tapeworms.
What is oncosphere larva?
(also onchosphere) Zoology. A tapeworm embryo or larva in the form in which it hatches from the egg, having a small, oval body bearing three pairs of chitinous hooks for attachment to the tissues of the intermediate host; a proscolex, a hexacanth.
Why are tapeworms called tapeworms?
The sum of the proglottids is called a strobila, which is thin and resembles a strip of tape; from this is derived the common name “tapeworm”. Proglottids are continually being produced by the neck region of the scolex, as long as the scolex is attached and alive.
What is the structure of tapeworm?
Tapeworms are bilaterally symmetrical (i.e., the right and left sides are similar). Some consist of one long segment; others have a definite head, followed by a series of identical segments called proglottids. The head, or scolex, bears suckers and often hooks, which are used for attachment to the host.
What is Hexacanth larva?
Hexacanth larva The micromeres develop into a hexacanth or oncosphere. The oncoblasts of the embryo secretes three pairs of chitinous hooks. This embryo with six hooks surrounded by two embryonic membranes is called as hexacanth larva or oncosphere.
What is a scolex?
Definition of scolex : the head of a tapeworm either in the larva or adult stage.
What is Plerocercoid larva?
Plerocercoid refers to last larval form, the infective form, found in the second intermediate host of many Cestoda with aquatic life cycles.
What is Miracidium larva?
The miracidium is a ciliated, nonfeeding larva (Fig. 9.18). Under favorable conditions, it escapes from the eggshell, usually through the operculum, into the environment. The miracidium is elongated and covered with flattened, ciliated epidermal plates.
Which of the following is a tapeworm?
Correct Option: C. Taenia is a genus of tapeworm that includes some important parasites of livestock. Members of the genus are responsible for taeniasis and cysticercosis in humans.
What is the life cycle of a tapeworm in humans?
Life Cycle. Taeniasis is the infection of humans with the adult tapeworm of Taenia saginata, T. solium or T. asiatica. Humans are the only definitive hosts for these three species. Eggs or gravid proglottids are passed with feces ; the eggs can survive for days to months in the environment.
Where do tapeworms attach to the small intestine?
The adult tapeworms attach to the small intestine by their scolex and reside in the small intestine . Length of adult worms is usually 5 m or less for T. saginata (however it may reach up to 25 m) and 2 to 7 m for T. solium.
Which cestodes are associated with cysticercosis?
The cestodes Taenia saginata (beef tapeworm), T. solium (pork tapeworm) and T. asiatica (Asian tapeworm). Taenia solium can also cause cysticercosis.
How long do Toxoplasma eggs survive in the environment?
Eggs or gravid proglottids are passed with feces ; the eggs can survive for days to months in the environment. Cattle ( T. saginata) and pigs ( T. solium and T. asiatica) become infected by ingesting vegetation contaminated with eggs or gravid proglottids .