The
gastrovascular cavity is the primary organ of
digestion and circulation in two major animal phyla: the
Cnidaria (including
jellyfish and
corals) and
Platyhelminthes (flatworms). The cavity may be extensively branched into a system of canals. In cnidarians, the gastrovascular system is also known as the
coelenteron, and is commonly known as a "blind gut" or "blind sac", since food enters and waste exits through the same orifice.