GENERAL HISTOLOGY

Detailed explanation-1: -The madreporite is a light-colored, calcerous opening used to filter water into the water vascular system of echinoderms. Acting as a pressure-equalizing valve, it is visible as a small red or yellow button-like structure (similar to a small wart) on the aboral surface of the central disk of a sea star.

Detailed explanation-2: -The madreporite is a sieve-like, calcified plate that connects the system to the aquatic environment. Water enters through the madreporite and flows through a tube, called the stone canal, that connects to the circular ring canal surrounding the mouth.

Detailed explanation-3: -The water vascular system consists of fluid-filled canals that extend to different parts of the body. Water enters the water vascular canal through the madreporite.

Detailed explanation-4: -Echinoderms are deuterostome marine organisms. This phylum of animals bear a calcareous endoskeleton composed of ossicles covered by a spiny skin. Echinoderms possess a water-based circulatory system. The madreporite is the point of entry and exit for water for the water vascular system.