BIO 2135 Lecture Notes - Mollusc Shell, Pericardium, Nephridium
17 Jul 2014
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Cilliated band: surrounds midline, traps food, propels towards mouth. Schizocoel metanephridia filtering coelomic fluid inside body cavity (ex. Dorsal heart (opposite to ventral nerve chord) and pericardial cavity (only annelidia and mollusca) Cavity fills with blood, gets put into heart then is squeezed out. Metanephridia: ciliated funnel suspended in coelomic fluid of body cavity, cilia beats and propels fluid in funnel, fluid passes down tubule and recover essential elements. Problem: any essential salts required by animal in coelomic fluid aren"t selectively filtered so processes fluid to recover nutrients so that at end of system, urine has only wastes to expel nephridiopore. Radula: grating structure on tongue used to grate organic material off substrate. Dorsal mantle: skin of epithelium, responsible for producing shell (first to hide in shell) Ventral cilliated muscular foot: foot, viscera on top, with mantle on top to secrete shell. Retractor muscles: to pull shell down against substrate.
