Crop (anatomy)

The goiter (Latin Ingluvies ) of the birds is a ballooning of the esophagus in the neck, immediately prior to the thoracic inlet. He is a food store and serve the pre-swelling of eingespeichelten food. The mucosa of the crop contains glands, these are the chicken in the " goiter road " in pigeons in the fundus; Digestive processes do not take place here ( but see Hoatzin ).

Species differences

The bolster is particularly well developed in birds that need to be able to take discontinuously larger amounts of food. In gallinaceous birds ( Galliformes ) provide a right-sided aneurysm of the esophagus dar. In pigeons birds ( Columbiformes ), the crop is in the form of two lateral bags.

In ducks, birds ( Anseriformes ), cormorants and the canary the crop, however, is only a fusiform dilatation of the esophagus.

Crop milk

When it comes doves in the crop during the breeding season to a thickening of the epithelium. Detached epithelial cells form a greasy, holokrines secretion, the so-called crop milk or milk pigeons. For Flamingos ( Phoenicopteridae ), this " milk " not only formed in the crop, but also in the rest of the upper digestive tract.

The crop milk is a whitish cream cheese -like mass. It is regurgitated by the parent animals and serves the diet of nestlings during the first days of life. It consists in pigeons to 65-81 % water, 13-19 % from protein and about to 7-13 % from fats.

Diseases

Diseases of the crop show up frequently in regurgitation.

A goiter inflammation ( Ingluvitis ) is a relatively common disease. It is rarely caused by bacteria but mostly by yeasts (→ Macrorhabdiose ) or trichomoniasis. Bacterial and yeast -induced goiter inflammation caused mostly secondary to mucosal injury by chuck parts or artificial diet. Rarely can form in the crop calculi ( stones goiter ). Kropffisteln are especially dangerous when the overlying skin is intact. Tumors of the crop may occur.