The tegument also protects the parasite from the hosts digestive enzymes and allows it to transfer molecules back to the host.The body form of adult eucestodes is simple, with a scolex, or grasping head, adapted for attachment to the definitive host, a short neck, and a strobila, or segmented trunk formed of proglottids, which makes up the worms body. Members of the subclass Cestodaria, the Amphilinidea and Gyrocotylidea, are wormlike but not divided into proglottids. Amphilinids have a muscular proboscis at the front end; Gyrocotylids have a sucker or proboscis which they can pull inside or push outside at the front end, and a holdfast rosette at the posterior end.The Cestodaria have 10 larval hooks while Eucestoda have 6 larval hooks. Scolex
The scolex, which attaches to the intestine of the definitive host, is often minute in comparison with the proglottids. It is typically a four-sided knob, armed with suckers or hooks or both. In some species, the scolex is dominated by bothria, or "sucking grooves" that function like suction cups. Cyclophyllid cestodes can be identified by the presence of four suckers on their scolices. Other species have ruffled or leaflike scolices, and there may be other structures to aid attachment.In the larval stage the scolex is similarly shaped and is known as the protoscoleces. Body systems
Circular and longitudinal muscles lie under the neodermis, beneath which further longitudinal, dorso-ventral and transverse muscles surround the central parenchyma. Protonephridial cells drain into the parenchyma.
When television presenter Michael Mosley deliberately infected himself with tapeworms he gained weight due to increased appetite. Dieters still sometimes risk intentional infection, evidenced by a 2013 warning on American television. Notes
References
Further reading

Merck Manual of Medication Information, Second Home Edition, Online Version, Tapeworm Infection 2005
Mayo Clinic Website on infectious diseases, Mayo Clinic - Tapeworm Infection, 2006
Medline Plus - Taeniasis (tapeworm infection)
University of South Carolina - School of Medicine - Cestodes (tapeworms)