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.
Circulatory System. Grasshoppers have an open circulatory system where the blood starts at the hemolymph, travels through large blood vessels, to the coelem, to the abdomen, and the heart in an open loop. The hemolymph contains chambers called sinuses which is similar to the heart of humans with four chambers.irculatory System. Grasshoppers have an open circulatory system where the blood starts at the hemolymph, travels through large blood vessels, to the coelem, to the abdomen, and the heart in an open loop. The hemolymph contains chambers called sinuses which is similar to the heart of humans with four chambers.