Freshwater hydra, jellyfish and coral polyps -these are typical intestinal cavities that are multicellular. What kind of lifestyle do they lead? What do they eat? Where do intestinal cavities digest food? Answers to these and many other questions can be found in our article.
General characteristics of intestinal cavities
Although they are multicellular,intestinal cavities have no tissues. So, they lack organs. A distinctive feature of the intestinal cavity is the presence of specialized cells that form two layers of the body. The external is called the ectoderm. It consists of intermediate, stinging, skin-muscular, sex and nerve cells.
The endoderm is the innermost layer of the intestinal cavity. This is the part of the body where the intestinal cavities digest food. Consider the features of this physiological process on the example of freshwater hydra.
Cavity digestion
Hydra is not capable of active movement.The sole, on the opposite side of which there is an orifice, performs the function of a peculiar sucker. Tentacles are located around it. Where do intestinal cavities digest food? This process begins in the body cavity.
Hydra infects small crustaceans and frywith stinging cells. Further tentacles prey moves through the mouth opening into the body cavity. The glandular cells that make up the endoderm, secrete a special secret, through which food breaks down into separate pieces.
Cellular Digestion
Next structure where the intestinal cavitydigest food, are digestive cells. They have flagella that create a stream of water. Due to this, food particles arrive at the cell surface. Here the next stage of its splitting will occur.
The digestive cells also have pseudopodia.These are non-permanent outgrowths of the cytoplasm. They take food, and it is inside the cells. There, in the digestive vacuoles, the final splitting process takes place. Undigested residues are also excreted through the oral opening.
So, we figured out where the intestinal cavitiesdigest food. This process takes place in two stages. All intestinal cavities are predators. With stinging cells they paralyze the prey. Tentacles that surround the mouth opening move it into the intestinal cavity. There begins the initial stage of digestion, which ends in specialized endoderm cells.
