Proglottid of a beef tapeworm, illustration

Proglottid (body unit) of a tapeworm Taenia solium, 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 illustration shows a proglottid of Taenia solium containing uterus with 7-13 primary lateral branches filled with eggs. The number of lateral branches is used in differential diagnosis with a beef tapeworm Taenia saginata, which contains 12-30 primary lateral branches., by KATERYNA KON/SCIENCE PHOTO LIBRARY