Madreporite
Imagine you have a colander full of pasta, and you're trying to drain out the water without losing any noodles. Similarly, a madreporite functions like a colander for an echinoderm, filtering water into its water vascular system while keeping unwanted particles out. Just as the colander allows water to pass through while retaining pasta, the madreporite allows clean water to enter the echinoderm's system, ensuring that only the necessary elements make it through, much like how you ensure only water escapes your pasta.
Practice Version
Madreporite: Sieve-like structure that filters particles from an echinoderms water vascular system. Madreporite. The madreporite is a small, porous plate on the surface of echinoderms that acts like a filter to manage water flow into their water vascular system.