Question

Circulatory system of echinoderms is _____________.
A. Closed
B. Open
C. Haemal
D. Both B and C

Answer 1

Hint: The echinoderms do not have any heart and use a water vascular system to bring oxygen to its very important organs, without blood or pulse. Examples of Echinoderms are starfish, brittle fish, sand dollar, etc.

Step by step answer:An open circulatory system may be defined as a cardiovascular system in which blood which is pumped by the heart passes through massive vessels into open areas or body cavities, referred to as sinuses. It is seen in arthropods and mollusks.
-A closed circulatory system is in which the blood pumped by the heart is often circulated through a closed network of blood vessels. This pattern is taken into account to be of a lot of advantages because the flow of fluid is often a lot of exactly regulated.
-Echinoderms have a different water system. This network of fluid-filled tubes in echinoderms helps them to perform various activities essential for life like breathe, eat, and move. Therefore, they'll perform without gill slits. Echinoderms even have an easy systema alimentarium, cardiovascular system, and systema nervosum. The systema alimentarium usually leads directly from the mouth to the anus. -The echinoderms have an associated open cardiovascular system, which means that fluid moves freely within the body cavity. However, echinoderms haven't any heart. This might flow from to their easy correspondence - a heart isn't required to pump the freely moving fluid. The invertebrate systema nervosum could be a nerve net of interconnected neurons with no central brain.
Hence, option B, i.e., open circulatory system is the correct answer.

Note: Water enters the system through the madreporite, flows through the stone canal, and enters the ring canal. variety of bulbous structures, known as Polian vesicles, that branch off of the ring canal function to keep up additional water stores. From the ring canal, water enters the radial canals that stretch into each of the arms, or rays. The lateral canals in the vascular system branch from the radial canal and convey the water into the ampullae and podia of the tube feet in echinoderms.