Morphology

Adult Worm

Taenia saginata attaches to the surface of the small intestine via four suckers located on the scolex (see image below). Unlike T. solium, no hooks are present on the scolex of T. saginata. The scolex has a maximum diameter of 1.5 to 2 mm while each sucker is approximately 0.7 to 0.8 mm in diameter. The worms have been observed to attain a length upwards of 25 meters, though are usually closer to 5 meters in length. Attached to the scolex is the neck and then thousands of proglottids (segments); the gravid proglottids have eggs in them. Aside from the gravid proglottids, which tend to brake off and leave in the feces, mature and immature proglottids are also present. Mature proglottids are close to 12 mm in bredth, while immature proglottids are longer (20 mm) but narrower (6 mm). Mature proglottids each have genital organs consisting of about 300 to 400 testes and a vaginal sphincter. The gravid proglottids are found in the last fifth of the worm and contain 15-20 lateral branches. T. solium, on the otherhand, contain only 7-13 lateral branches. The difference in the branching of the gravid proglottids is a method of diagnosis in determing which tapeworm is infecting the individual.

Eggs

The eggs of both T. solium and T. saginata are indistinguishable. Eggs develop in hyaline capsules and are shed after leaving the proglottid. The eggs contain an outer membrane and are roughly 31-43 um in diameter. These eggs are ingested by cattle or other intermediate hosts and once they reach the duodenum, hatch and penetrate the intestinal wall.

Cysticercus

The cysticercus (for image click "Transmission" on left frame) develop and appear in striated muscle and is more concentrated in certain muscle, particularly the pterygoid, tenderloin, and myocardium areas. The mature cysticercus are in the shape of an oval and are milky-white. They are 7.5-10 mm in breadth and 4-6 mm in length.

Scolex of T. saginata

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