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.

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. Figure 3.85 shows some examples of echinoderm tube feet. Tube feet extend through the small holes in the skeleton to the outside.

Detailed explanation-3: -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-4: -The tube feet of echinoderms move and handle food using a hydraulic system. “Something similar happens in echinoderm tube feet–small, soft, unjointed, and exceedingly numerous organs used for locomotion, handling food, and similar functions, noticeable when a starfish creeps up the glass wall of an aquarium.

Detailed explanation-5: -Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on brittle stars, and have only a feeding function in feather stars.