Final answer:
The coelomic cavity of sea stars is divided into sections that house their digestive glands, gonads, and tube feet, which are essential for various functions including feeding and locomotion. The water vascular system, indicated by the presence of the madreporite, is also a key feature of their anatomy.
Step-by-step explanation:
In echinoderms like sea stars (class Asteroidea), the coelomic cavity is divided into sections that have various functions. Notably, the sea stars' anatomy is characterized by a central disc from which arms extend. Each arm contains a range of structures, such as digestive glands, gonads (reproductive organs), and tube feet. The tube feet are especially important, as they are used for locomotion, feeding, and sensation, as well as anchoring the sea star to the substrate. Furthermore, the madreporite plays a crucial role in the sea stars' water vascular system, which is their defining characteristic, by allowing water to enter the stone canal leading into the coelomic cavity.