The main regions of a typical mollusk's body is head foot and visceral mass. The Mollusks are soft bodied invertebrates. They have 4 body parts that are head and foot, shell, visceral mass and mantle. The main two parts are the head and foot and visceral mass. The Visceral mass is where digestion, respiratory, reproductive and excretory are held. On the other hand the foot is used to give a sense of balance and the head is used to carry one or two tentacles.