The Water Vascular System:
The water vascular system provides water pressure to the feet of the star fish. They are called "tube feet" and they help the animal suction onto their prey. They also help them get around, open prey's shells, and they exchange gases and nitrogen waste. This system contains the central canal, ampulla, radial canals, and the tube feet. The opening is called this madreporite, and this is where water enters and exits. The water travels from the madreporite to the ring canal, and then it goes to the radial canals on each arm of the starfish. They then go to the tube feet where the provide suction.
More information on their anatomy: BiologyWise
Important Vocabulary:
