Stomachs in Birds
Birds have a glandular stomach, or proventriculus, and muscular stomach or gizzard. The glandular stomach receives food from the esophagus, and secretes mucus, HCl and pepsinogen, similar to what is seen in the mammalian stomach. The gizzard is a disk shaped, very muscular and in many birds contains small stones that facilitate grinding of foodstuffs. One of the gizzard’s two orifices receives ingesta from the glandular stomach and the other empties into the duodenum.