Comparative histological studies on the renal medulla in broiler chicken and broiler duck

Kidneys of six each of adult broiler chicken and broiler ducks were used in the present study. In the histological studies, the kidneys of all studied birds showed two zones, the cortex and medulla. The medulla occupied only a small portion of the kidney. In chicken a greater number of distinct cone-shaped medullary lobules were seen among cortical lobules while in duck they were lesser in number, more rounded in outline and were not cone shaped as in chicken. In the case of chicken more than one cortical lobule drained into a medullary lobule. Mammalian type of nephrons that occupied the juxta medullary region presented loop of Henle that was located within the medullary cone. Collecting ducts from different medullary lobules united together to form several large collecting ducts within the medulla which in turn united to form ureteral branches.