Proglottid of a beef tapeworm, illustration

Proglottid (body unit) of a beef tapeworm (Taenia saginata), computer illustration. Tapeworms are a type of flatworm that can parasitize animal and human intestines. Body segments called proglottids are budded off from the head and neck region of the tapeworm while the tapeworm grows in the intestine. Tapeworms have no digestive systems of their own but absorb directly through their skin the food ingested and broken down by the host. Tapeworms can cause diarrhoea, weight loss and abdominal discomfort in humans. Adult tapeworms may grow 5-10 meters in length. The illustrations shows a proglottid of Taenia saginata containing uterus with 12-30 primary lateral branches filled with eggs. The number of lateral branches is used in differential diagnosis with a pork tapeworm, Taenia solium, which contains 7-13 lateral branches., by KATERYNA KON/SCIENCE PHOTO LIBRARY