THE MORPHOLOGY OF CROP’S CHICKENS IN PRENATAL PERIOD OF ONTOGENESIS
The material for the study was selected from prefetuses and fetuses of chicken cross Shever 579 for 10, 15 and 20 days of incubation (10 in each age group). Classical methods of histological investigation were during studies. We found that 10 days incubation prefetuses of chickens crop is well developed. In it the formation of mucous, muscular and adventisia shell takes place. In the mucosa surface epithelium cells, lamina propria and submucosa containing fibroblastic and mesenchimal cells, between them muscle plate is not expressed. The muscular coat is constructed of smooth muscle tissue, the cells of which form two layers: an inner-circular and outer longitudinal. Among them there are number of fibroblastic cells. Adventisia is poorly developed. It is formed by mesenchimal cells and fibroblastic series. In all wall shells of crop the formation of blood vessels take place. In chickens 15-days old fetus continues forming of membranes of the crop. In the mucosa surface epithelium thickens, lamina propria and submucosa is formed by loose connective tissue, between them formation of muscular shell takes place, which is represented by bundles of smooth muscle cells. In the lamina propria and submucosal glandular part of an crop there are dense clusters of epithelial cells, which form secretory glands departments and their ducts. The inner layer of muscle membrane partially invaginates in large folds of mucous membrane. Adventisia formed by loose connective tissue. In chickens 20-days old daily fetuses wall of crop is completely formed. The epithelium of the mucosa is squamous not keratinizing. Secretory departments of glands and their ducts in the glandular part of crop are well defined. Muscular coat has three layers of smooth muscle cells: inner and outer - longitudinal and middle - circular. Adventisia shell is well defined. It increases the number of blood vessels.