BIOL 1604 Lecture Notes - Lecture 8: Schistosomiasis, Cysticercosis, Schistosoma
Document Summary
Triploblastic: presence of three tissue levels. Cephalization: concentrating sense organs in the head regions. Aceolomates do not have an extra cavity only the gut cavity. Packing tissue contains more cells and fibers and less extracellular matrix than dos the mesoglea of cnidarians. Muscular system primarily a sheath form of mesodermal origin. Layers of circular longitudinal and sometimes oblique fibers beneath the epidermis. Incomplete gut or no gut: extracellular and intracellular digestion (enzymes and phagocytosis) Osmoregulation: canals with tubules that end in protonephridia (flame cells). Simple nerve net to centralized nerve net. Pair of anterior ganglia with longitudinal nerve cords connected by transverse nerves in most forms. Sense organs: statocyst, ocelli, rheoreceptors, auricles. Direct development or indirect with different larval stages. Class turbellaria: freshwater planarians, free living, mainly marine, terrestrial, predators, scavengers, herbivores, very few commensals or parasites. Digestive cavity varies from none to simple to highly branched. Muscular and ciliary movement: cilia, mucus, muscular undulations.
