| 词条 | Gastrovascular cavity |
| 释义 |
| align = left | direction = horizontal | width = 240 | image1 = Jellyfish cross section numbered.svg | width1 = 665 | alt1 = | caption1 = The gastrovascular cavity or coelenteron of the flower hat jelly, Olindias formosa (arrow #2, colored gray) | image2 = Dugesia Anatomy schematic.svg | width2 = | alt2 = | caption2 = Gastrovascular system of the flatworm Dugesia, colored red }} 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. The radially symmetrical cnidarians have a sac-like body in two distinct layers, the epidermis and gastrodermis, with a jellylike layer called the mesoglea between. Extracellular digestion takes place within the central cavity of the sac-like body. This cavity has only one opening to the outside which, in most cnidarians, is surrounded by tentacles for capturing prey. References
2 : Cnidarian biology|Digestive system |
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