GENERAL HISTOLOGY

Detailed explanation-1: -The water vascular system is a hydraulic system used by echinoderms, such as sea stars and sea urchins, for locomotion, food and waste transportation, and respiration. The system is composed of canals connecting numerous tube feet.

Detailed explanation-2: -Excretion in echinoderms is by simple diffusion of metabolic wastes (ammonia) across thin permeable regions of the body wall. A variety of gas exchange structures, including the tube feet, is found in various echinoderms.

Detailed explanation-3: -Sea stars have a water vascular system and tube feet much like those of the sea urchins. Ambulacral grooves (from the Latin root ambul meaning walk) are narrow channels in the oral surface of a sea star filled with tube feet. The tube feet are used mainly for grabbing and locomotion.

Detailed explanation-4: -Echinoderms possess a unique ambulacral or water vascular system, consisting of a central ring canal and radial canals that extend along each arm. Water circulates through these structures and facilitates gaseous exchange as well as nutrition, predation, and locomotion.

Detailed explanation-5: -They use their tube feet to attach to rocks, but also for locomotion. All echinoderms have tube feet. Like we mentioned in the introduction, tube feet help the animal to move and hold onto the rocks. Another characteristic of echinoderms is that they are capable of regeneration.