Molluscs

 Snails

The surface of the snail’s body is covered with a layer of cells that build up the epidermis. Numerous glands, which extract slime, are found under the layer that helps the snail to move. The snail’s nervous system is well developed and it consists of several ganglions. They stimulate the head, the foot, the digestive system, and the shell. The snail has large tentacles on the head (bubble-shaped eyes) and small tentacles (for the sense of touch, smell and balance).
The digestive system starts in the mouth, so they eat using a radula to pound the food, and then continues the larynx and the gullet that passes into the stomach. The food in the mouth mixes with the slime of the saliva gland. Blood spreads the nutrients through the body and undigested material is extracted through the anus.
The heart consists of one ventricle and one atrium. The snail uses so-called kidneys for extraction; it is a hermaphrodite and has internal fertilization.