Digestive system of gastropods the food forward in a steady stream from the mouth. Usually, the food is embedded in a string of mucus produced in the mouth, creating a coiled conical mass in the style sac. This action, rather than muscular peristalsis, is responsible for the movement of food through the gastropod digestive tract. Two diverticular glands open into the stomach, and secrete enzymes that help to break down the food. In the more primitive species, these glands may also absorb the food particles directly and digest them intracellularly. The hepatopancreas is the largest organ in stylommatophoran gastropods. It produces enzymes, and absorbs
Acidic oxide Acidic oxide Acidic oxides, or acid anhydrides, are oxides that react with water to form an acid, or with a base to form a salt. They are oxides of either nonmetals or of metals in high oxidation states. Their chemistry can be systematically understood by taking an oxoacid and removing water from it, until only an oxide remains. The resulting oxide belongs to this group of substances. An inorganic anhydride (a somewhat archaic term) is acid anhydride without an organic moiety. Acidic oxides are not Brønsted–Lowry acids because they do not donate protons; however, they are Arrhenius acids because they