Gizzard

Definition

A gizzard is a specialized stomach found in some animals, including birds, reptiles, and earthworms, used for grinding food. It often contains ingested stones or grit to aid in the mechanical breakdown of tough food items.

5 Must Know Facts For Your Next Test

1. The gizzard is part of the digestive tract and works in conjunction with other organs like the crop and the stomach.
2. Birds commonly ingest small stones that lodge in the gizzard to help grind seeds and other hard materials.
3. Not all animals have a gizzard; it is absent in mammals but present in birds, some reptiles, fish, and earthworms.
4. Gizzards are highly muscular and can contract powerfully to crush food items before they move on to the intestines for further digestion.
5. In birds like chickens and turkeys, the gizzard plays a crucial role in facilitating efficient nutrient absorption by breaking down tough plant material.

Review Questions

• What is the primary function of a gizzard?
• Which types of animals typically possess a gizzard?
• How does the presence of ingested stones or grit benefit the function of a gizzard?

Related terms

Crop:

A storage organ found in birds where food is softened before moving to the stomach and gizzard.

Proventriculus: The glandular part of a bird's stomach where initial digestion occurs before food enters the gizzard.

Mechanical Digestion: The physical breakdown of large pieces of food into smaller pieces without chemical change.