n a committee set up to prepare and arrange topics to be discussed, the order of business, etc., for a legislative assembly or other body. vigilance committee. n (in the U.S.) a self-appointed body of citizens organized to maintain order, punish crime, etc., where an efficient system of courts does not exist.
Best Answer: Annelids have closed circulatory systems, which means that blood is always contained by blood vessels. Some mollusks and arthropods, on the other hand, have open circulatory systems, which means that at some time, blood from the heart will pump into the hemocoel or blood cavity.n Annelids, the blood vessels end up with capillaries. Hence called closed BVS. In cockroach it is open BVS as blood vessels don't end up with capillaries. Hence, the blood vessels bluntly open into body cavities. NOTE: Circulatory system is also called BVS.
Arthropods and mollusks have an open circulatory system. In this type of system, there is neither a true heart or capillaries as are found in humans. Instead of a heart, there are âblood vessels that act as pumps to force the blood along. Instead of capillaries, blood vessels join directly with open sinuses.