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.
Worms have two main blood vessels: a dorsal and a ventral vessel. These vessels circulate blood from the head to the tail of their bodies. The blood is moved from waves of contraction in the vessel. Both humans and worms are alike in that they both have what is referred to as a 'closed circulatory system'.   A crayfish has an open circulatory system while humans have a closed circulatory system. Closed means that we have true blood vessels that carry blood to and fro â¦ m the heart. Open means that the organs are simply bathed in blood that freely circulates around the body.