These podocytes are connected by an internal system of canals to the madreporite, where water enters the stone canal. The adult echinoderm typically has a spacious and fluid-filled coelom. Cilia aid in circulating the fluid within the body cavity, and lead to the fluid-filled papulae, where the exchange of oxygen and carbon dioxide takes place, as well as the secretion of nitrogenous waste such as ammonia, by diffusion.
Madreporite
Podocytes—cells specialized for ultrafiltration of bodily fluids—are present near the center of the echinoderm disc, at the junction of the water vascular and hemal systems.
Source & attribution
Biology 2e — Superphylum Deuterostomia
OpenStax contributors · OpenStax, Rice University
CC BY 4.0. Text excerpted; whitespace normalised and empty cross-references removed; learning prompts added. No illustrations reproduced.
Source edition: 2024-12-20T02:54:45Z
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