The members of the phylum Platyhelminthes are called flatworms because their bodies are flattened a. posteriorly. The cells that secrete mucus in the epidermis of the Turbellaria are called a. parenchyma. The body of the parasitic flatworms is covered in a syncytial layer called a. parenchyma. The cells that form a meshwork filling the spaces between the muscles and organs that develops from the mesoderm is called a. parenchyma. While the previous phyla have used intracellular digestion, within these three phyla extracellular digestion is the norm.
Extracellular digestion means that a. proteolytic enzymes are secreted into the gut.
Another name for a protonephridium is a a. syncytial layer. The protonephridia function in a. waste disposal. The light-sensitive sense organs in the flatworms are called a. rheoreceptors. The sense organs that respond to changes in water current directions are the a. rheoreceptors. The sense organs of the flatworm that help the organism maintain its equilibrium are called a. rheoreceptors.