Tuesday, March 6, 2007

Excretion

-Annelids produce two kinds of waste, solid and metabolism wastes.
-The solid wastes are excreted by anus.
-The wastes that come from metabolism are excreted by nephridia.
-A pair of nephridia in each of the septa excretes the wastes out of the body to the outside.

Example (Earthworms):
-The excretory system in earthworms consists of a pair of nephridia for each segment.
-Each nephridia consists of a long, convoluted tubule that begins with a ciliated funnel.
-Fluid is carried into the funnel by the beating of the cilia and is excreted through an outer pore.

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