Answer:
Proventriculum and gizzard
Explanation:
In birds, the stomach is divided into two compartments: the proventriculum and the gizzard. These structures are less distinct in carnivorous species, and well-prominent in grain and seed-feeding species.
The proventriculum is a structure located between the lower esophagus and the gizzard. It is covered by a glanular mucous layer with secretory function and is therefore responsible for the secretion of enzymes and hydrochloric acid for digestion.
The gizzard is considered a muscular stomach, responsible for crushing and macerating food (as in chewing). It has a highly developed and strong musculature, resistant to the action of hydrochloric acid.
