Sea Star Internal Anatomy

Echinoderm

Cardiac Stomach

can be everted through the mouth to envelope prey

site of initial digestion

Pyloric Stomach

receives secretions of digestive glands for chemical digestion

Digestive Glands

secretes digestive enzymes for breakdown of food

absorption and storage of food materials

Rectal Ceca

small branches that increase the surface area of the intestine for more efficient nutrient absorption

Gonads

produce gametes for reproduction

Ring Canal

portion of water vascular system encircling mouth

Radial Canals

portions of water vascular system from ring canal and leading into each arm

Stone Canal

portion of water vascular system leading from madreporite to the ring canal

Madreporite

porous entrance to water vascular system that serves as both pressure regulator and simple filter

Ampullae

provide hydaulic pressure for movement of tube feet

Ossicles

form and support structure of endoskeleton