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
Development of the digestive system anterior region (future urogenital sinus). The urorectal septum divides the two regions and breakdown of the cloacal membrane covering this area provides communication to the exterior for the anus and urogenital sinus. The upper part of the anal canal is derived from endoderm of the hindgut. The lower part (one-third) is derived from ectoderm around the proctodeum. Ectoderm, in the region of the proctodeum on the surface of part of the cloaca, proliferates and invaginates to create the anal pit. Subsequently, degeneration of the cloacal membrane establishes continuity between the upper and lower parts of the anal canal. Abnormalities in