the small intestine is a part of the digestive system
digestive_tract is body_part. digestive_system has pancreas_and_small_and_large_intestines small_intestine is intestine. digestive_tract is internal_body_part. digestive_system is system. mammal_digestive_tract is body_part. digestive_tract is organ_system. small_intestine_tissue_cells is intestinal_cell. small_intestine_tissue is intestinal_tissue. small_intestine is internal_organ.