Transformation of the Permanent Zone of the Adrenal Cortex in Mature and Premature Infants

Abstract

The development of the permanent adrenal cortex of the fetus in the last quarter of gestation was histometrically examined. The volume of the permanent cortex did not increase in proportion to the total adrenal or body weight, but its growth kept pace with increase of adrenal surface area. The thickness of the permanent cortex did not essentially increase with the progress of fetal months.
The permanent cortex was composed of columnar lobules demarcated by reticulin fibers. The diameter of the lobules became smaller with advancing fetal months, on account of subdivision of the lobules by invading reticulin fibers. The maturation of the permanent cortex in late pregnancy consisted consequently in subdivision of the lobules but not in an increase in the height of the lobules.
The difference in the behavior of the permanent cortex between mature and premature newborns was that in the course of normal development. No deviation from the normal development was found in the permanent adrenal cortx of the premature.