A combination of factors is likely causing the decline of blue spruce trees throughout Michigan. Posted on March 7, 2011 by Dennis Fulbright, Michigan State University Extension, Department of Plant Pathology, and Jill OâDonnell, Michigan State University Extension.
Flatworms lack a respiratory or circulatory system; these functions take place by absorption through the body wall. Nonparasitic forms have a simple, incomplete gut; even this is lacking in many parasitic species. Movement in some flatworms is controlled by longitudinal, circular, and oblique layers of muscle.
PLATYHELMINTHES DIGESTIVE SYSTEM. This Phylum, as mentioned before, has a different and unique kind of digestive system compared to other flatworms. This is because it only has one opening for it's digestive system which is also used for it's mouth but not anus making their digestive tract incomplete.The Platyhelmthes uses it's mouth, pharynx, and intestine for its digestive system.t works but sucking food into the intestine where phagocytic cells of the gastrodermis complete digestion. The Cestoda, one of the three classes of the Platyhelmthes, does not have a digestive system and the rest of the parasitic classes rely on the host for digestion.