[STRUCTURAL TRANSFORMATION OF CRANIAL CAVAL VEINS IN POSTNATAL ONTOGENESIS (A MORPHOMETRIC STUDY)]

The peculiarities of structural transformations of different portions of the cranial caval veins were studied in 60 rats at Days 1-30 after birth. The alternating periods of rapid and slow increase in the length of the cranial caval veins were identified. Wall thickness in all the parts of the right cranial caval vein increased less significantly as compared with its length during the early period after birth (Days 1-11). At Days 16-30, the rate of growth of the length was reduced, while the vessel wall thickness increased. This regularity was not observed in the development of the left cranial caval vein. Instead, this vessel demonstrated alternating periods of accelerated and decelerated growth of the wall thickness.