Conduction and Storage Region

Conduction and Storage Region
The esophagus of vertebrates and many invertebrates serves to transfer food to the digestive region. In many invertebrates (annelids, insects, octopods) the esophagus is expanded into a crop (Figure 34-9), used for food storage before digestion. Among vertebrates, only birds have a crop. This crop serves to store and soften food (grain, for example) before it passes to the stomach, or to allow mild fermentation of food before it is regurgitated to feed nestlings.