Morphological and morphometical study of the ovine kidneys during the fetal period

BACKGROUND: The study of animal development by a dynamic perspective on gross anatomy often provides amplified pattern to reveal the more complex anatomy of the adult. This is especially helpful in understanding system whose components drastically change their relation positions during developmental growth, such as urogenital organs. OJECTIVES: The aim of present study was to study morphologic and morphometric development of sheep kidneys during fetal period. METHODS: Sixty fetal kidneys obtained from 30 sheep fetuses were divided into three groups (70-100, 100-120, 120-145 days) according to body length. Topography, dimensions, and weight of kidneys were evaluated. RESULTS: The kidneys were located totally in the lumbar region of the sides of the median plane. The position of kidneys relative to the transvers process of lumbar vertebrae was different in the age groups. The fetal kidney was not located at the same level of adult position even at the end of fetal period. The right kidney was consistently slightly cranial to left kidney. The left kidney was in contact with dorsal sac of rumen in all age groups. The right kidney was covered by ventral surface and a small part of the lateral surface of right lobe of liver, but with advancing age, the contact are of right kidney with caudate process of liver showed tangible reduction and such a contact limited eventually to the cranial pole of kidney. Means of dimensions and weight of kidneys increased with gestational age during fetal period. There were no sex and laterality differences in any parameters. CONCLUSIONS: Topography of fetal sheep kidneys relative to the lumbar vertebrate and their contact area of the kidneys with right lobe and caudate process of liver differed extremely from that of adult sheep kidney. It seems that the emergence of positional asymmetry of kidneys and changing contact area of right kidney exhibited an intimate relationship with the cranial shift and grow rate of right lobe and caudate process of liver during fetal development. The morphmetric results of fetal sheep kidneys were in agreement with the morphometric findings of humans and bovine kidneys.