The Human Digestive System Quiz Diagram, 4th, 5th, 6th, grade science quiz online. This is a biology quiz for students to learn how to label the different parts of the human digestive system: the mouth, esophagus, stomach, small intestine, pancrease, gall bladder, large intestine, anus. This quiz contains and interactive diagram with drag and drop functions. This is an interactive exercise and there is more practice under same topic in the printable worksheets section. Have fun learning about the digestive system.