A Histological Study on the Developing Adrenal Gland in Human Fetuses

Abstract

Background: Adrenal gland has an outer cortex and inner medulla that vary structurally, functionally, and embryologically. The developing gland plays a major role in concordance development of various viscera of the fetus and in parturition. The fetal adrenal gland shows histological changes not only in the fetal cortex but also in capsule, permanent cortex, and medulla. The current study aims to look at the changes in the microstructure of the fetal adrenal glands at various gestational ages. Methodology: Forty adrenal specimens from dead fetuses of gestational age from 14 to 36 weeks were collected and processed for routine hematoxyline and eosin staining and studied under light microscope. The samples were grouped into I, II, and III based on their gestational age. The microscopic changes occurring in different gestational ages were studied and photographed. Results: The cortex become well defined by 18 weeks and increase in thickness till term. Blood vessels appear in the capsule as early as 15 weeks. The fetal cortex increases in thickness with increase in gestational age. Lymphocytic infiltrations were consistently noted in the permanent cortex. The neuroblastic nodules were noted in the medulla from 14 weeks and regressed with advancing gestational age. Conclusion: Increase in the size of the fetal adrenal gland is mainly due to the increase in the fetal cortex. The neuroblastic nodules were seen until 32 weeks of gestation. The lymphocytic infiltration in the fetal cortex opens a new avenue of research to study their role in mediating the cortical secretions in fetus.

Non-classical animal models for studying adrenal diseases: advantages, limitations, and implications for research

“…Similarly to humans, the adrenal cortex of pigs consists of three morphological layers: the ZG, the ZF, and the ZR [ 114 ]. The end products of steroidogenesis are identical to those of humans.…”