Cow tongue with parasitic tapeworm cysts

Photograph of a sagittal section of the tongue from a cow showing numerous pea-sized parasitic cysts. These are the larval stages of the beef tapeworm of humans, Taenia saginata. This stage is called Cysticercus bovis and has a different name to the adult tapeworm because early scientists did not realise that they both belonged to the same life cycle when naming them. Eating raw or undercooked beef containing these cysts will results in humans becoming infected with the adult tapeworm in their small intestine. Note that each cyst has a single immature tapeworm head inside ready to develop into an adult tapeworm up to 15 m long.