In a more exact definition, the scolex is the anterior, tiny and globose end of the tapeworm and other cestode worms, made up of the head and the organs that allow it to be attached to the wall of the digestive tract of the being it parasitizes, that is, it is the Cephalic portion of adult parasites of cestode- class. On the scolex, there are piglets or hooks (depending on the species) that allow it to adhere to the mucosa of its host's intestine. All tapeworms have scolex, as well as other worms of importance to man, such as those of the genus Hymenolepis.
The scolex has different shapes depending on the organism. Some are oval in shape, others are quadrangular or pyriform. The elements in the scolex that allow the parasite to adhere to the intestine are called suction cups and there are usually four.
In the center of the scolex, some worms have a median protrusion conspicuously protruding rostellum or rostelum, which may be retractable, like that of Hymenolepis nana and is generally "armed" with a crown of one or more rows of thick hooks or aculeus, as in the case of Taenia solium, but it also lacks hooks like Hymenolepis diminuuta and Taenia saginata, which is why they are called “disarmed”.
Usually the size of a common scolex is 2 mm, even though the parasite is several meters long. Following the scolex continues the neck, shorter and thinner, which is the point where the growth of the rest of the worm's body begins, called “stroboscopic”.
The scolex is very useful in the clinical laboratory, since it is one of the factors that allows one to distinguish one cestode from the other, particularly those belonging to the same genus. Thus it is possible to differentiate between a diminutive H. and H. nana, such as T. saginata T. solium. It is a great diagnostic tool along with differences in size, neck and strobes between one species and another. However, because the scolex is buried in the intestinal mucosa, it is rarely expelled in feces, making the laboratory diagnosis almost always based on finding and distinguishing eggs from the host's anal region or free proglottids in the fecal cake..
