GENERAL HISTOLOGY

Detailed explanation-1: -The system is composed of canals connecting numerous tube feet. Echinoderms move by alternately contracting muscles that force water into the tube feet, causing them to extend and push against the ground, then relaxing to allow the feet to retract.

Detailed explanation-2: -An echinoderm moves by using many tube feet. Tube feet are small, delicate projections attached along the side of a water-filled tube called a radial canal.

Detailed explanation-3: -water vascular system is used mainly for locomotion. The inner wall of the water vascular canals are provided with cilia. The beating of the cilia causes the seawater to enter through the madreporite. Finally, the seawater reaches the tube feet and their ampullae.

Detailed explanation-4: -Circulation and respiration: Starfish are almost unique in the fact that, unlike most other animals, they do not have blood but instead use sea water to pump around their bodies. The water vascular system uses cilia and the constantly contracting ampullae to keep things moving.