includes mouth, crop (storage), gizzard (grinding structure), intestine circulatory system is closed contractile aortic arches pumping blood (acting as "hearts") dorsal and ventral vessels carry blood to/from body respiratory system varies;
(vessels; carry; blood; to; from body respiratory system) (aortic arches pumping blood (; varies; ) (intestine circulatory system; is closed; ) (aortic arches; pumping; blood)
vessels aortic arches pumping blood ( intestine circulatory system aortic arches
carry varies is closed pumping
blood to from body respiratory system
blood