1. The muscular, glandular chamber of a bird's stomach that secretes digestive enzymes and precedes the gizzard.
Usage: ornithology; anatomy
2. In insects and other invertebrates, a muscular enlargement of the esophagus that functions in food storage or processing.
Usage: zoology; entomology

Examples

• The proventriculus of the chicken secretes gastric juices that begin breaking down food.
• In birds, the proventriculus works together with the gizzard to digest seeds and grains.
• The insect's proventriculus acts as a temporary storage organ before food moves to the midgut.
• Veterinarians examine the proventriculus during avian necropsies to assess digestive health.
• The proventriculus is lined with glands that produce pepsin and other enzymes.