blood is a part of the circulatory system
circulatory_system is body_part. vertebrate_circulatory_system is body_part. blood is body_part. circulatory_system is organ_system. mammal_circulatory_system is not body_part. mammal_circulatory_system is body_part. mammal_circulatory_system is circulatory_system. blood_vessel is circulatory_conduit. circulatory_system is not body_part. circulatory_system is internal_body_part.