Ambulacral (water vascular) system

Definition

The ambulacral (water vascular) system is a network of hydraulic canals unique to echinoderms, such as sea stars and sea urchins. It functions in locomotion, feeding, and gas exchange through a series of tube feet.

5 Must Know Facts For Your Next Test

1. 1. The ambulacral system operates via hydrostatic pressure generated by water intake through the madreporite.
2. 2. Tube feet are the primary structures used for movement and are extended or retracted by varying internal water pressure.
3. 3. The system includes five main components: the madreporite, stone canal, ring canal, radial canals, and tube feet.
4. 4. This system also plays a role in respiration and excretion by facilitating gas exchange through its tube feet.
5. 5. Echinoderms can use their water vascular system for predation, such as everting their stomachs to digest prey externally.

Related terms

madreporite:

A sieve-like structure on the surface of echinoderms that allows seawater to enter the water vascular system

tube feet:

Small, flexible appendages operated by hydraulic pressure within the water vascular system used for movement and feeding

radial canal: Extensions from the ring canal that run along each arm of an echinoderm distributing water to tube feet