Snails (lat. Gastropoda) are one of the eight classes in the knee molluscs.
Area snail's body is covered by a layer of cells that make up a skin (epidermis). Beneath it there are many glands that secrete mucus by which the snail to move. The snail's nervous system is well developed and consists of several ganglia. They stimulate the head, foot, intestine and mantle. She wears a large tentacles (bubble-shaped eyes) and small tentacles (touch, sense of balance and sense of smell).
The digestive system begins to mouth where there are boards for chopping food, then continues on the mouth pharynx, and esophagus, which passes into the stomach. The food in the mouth mixes with mucus salivary glands. Blood spreads the nutrients by the body and undigested particles extracted through the anus.
Snails have an open circulatory system which is the evolutionary progress. Their blood after leaving the vessel enters the hollow space between the bodies. From there, the blood cells teaches nutrients and oxygen and takes harmful substances resulting cell respiration and relates them to the authorities that they secrete.
The heart consists of one ventricle and one atrium. For secretion snail uses so-called kidneys.
Snails are hermaphrodites, and mostly has internal fertilization.
Better known on land snails are vinogradnjak, striped curb. In the sea are common snail murex, limpet, snail and others.
Uploaded: Oct 5, 2015