Freshwater hydra, jellyfish and coral polyps are typical intestinal animals that are multicellular. What kind of lifestyle do they lead? What do they eat? Where do the intestinal digest food? You will find answers to these and many other questions in our article.
General characteristics of the intestinal
Despite the fact that they are multicellular, in the intestinal there are no tissues. This means that they lack organs. A distinctive feature of the intestinal cavity is the presence of specialized cells that form two layers of the body. The outer one is called ectoderm. It consists of intermediate, stinging, musculocutaneous, reproductive and nerve cells.
The endoderm is the inner layer of the body of the intestinal cavity. This is the part of the body where intestinal cavities digest food. Consider the features of this physiological process on the example of freshwater hydra.
Digestive digestion
Hydra is not capable of active movement. The function of a kind of suction cup in them is performed by the sole, on the opposite side of which there is a mouth opening. Around it are tentacles. Where do the intestinal digest food? This process begins in the body cavity.
Hydra infects small crustaceans and fry of fish with stinging cells. Next, tentacles prey moves through the oral opening into the body cavity. The glandular cells that make up the endoderm secrete a special secret through which food breaks up into separate pieces.
Cell digestion
The next structure, where the intestinal cavity digests food, is the digestive cells. They have flagella creating a current of water. Due to this, food particles enter the surface of the cells. Here the next stage of its splitting will take place.
Digestive cells also have pseudopods. These are intermittent outgrowths of the cytoplasm. They capture food, and it is inside the cells. There, in the digestive vacuoles, the final splitting process takes place. Undigested residues are also released through the mouth opening.
So, we figured out where the intestinal cavities digest food. This process takes place in two stages. All coelenterates are predators. Using stinging cells, they paralyze prey. The tentacles that surround the oral opening move it into the intestinal cavity. There, the initial stage of digestion begins, which ends in specialized cells of the endoderm.