the intestines are a part of the digestive system
digestive_tract is internal_body_part. mammal_digestive_tract is body_part. digestive_system is system. digestive_system has esophagus_and_stomach digestive_tract is not body_part. digestive_system has liver_and_gallbladder digestive_system has pancreas_and_small_and_large_intestines digestive_tract is organ_system. digestive_tract is body_part. digestive_tract is not internal_body_part.