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.
Closed circulatory system Vertebrates, and a few invertebrates, have a closed circulatory system. Closed circulatory systems have the blood closed at all times within vessels of different size and wall thickness.In this type of system, blood is pumped by a heart through vessels, and does not normally fill body cavities. Open circulatory system The open circulatory system is common to molluscs and arthropods.Open circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.pen circulatory systems (evolved in crustaceans, insects, mollusks and other invertebrates) pump blood into a hemocoel with the blood diffusing back to the circulatory system between cells.