Development and Maturation...G T N Sangma, Yumnam Ibochouba, Ningthoujam Damayanti

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2 Development and Maturation...G T N Sangma, Yumnam Ibochouba, Ningthoujam Damayanti Results And Observations: GROSS structure: During early fetal period till about 16 weeks suprarenals are seen as yellowish tongue shaped mass, obliquely oriented and disposed overlapping the superomedial poles of the corresponding kidneys upto its hilum (fig. 1). No major difference in shape of right and left suprarenal is noted till about 18 weeks of development. The growth of suprarenal is gradual and steady except spurts noticed around 18th to 24th weeks and from 32nd week till term (Table I). The left is found consistently heavier than the right throughout fetal periods (Table II). Between 9 to 16 weeks both suprarenals are tongue shaped, yellowish mass related to superomedial poles of the corresponding kidneys, extending upto the level of hilum on medial side. The anterior surface is slightly concave and cover the anterior surface of the corresponding kidney while the posterior surface is smooth and is found in the same plane as the posterior surface of the kidney with no superimposition. Hilum at this stage is represented by a faint line running parallel to the superior border of the suprarenal in its middle part. At 16 to 22 weeks the difference in the shape of the suprarenals is noticed, the right becoming tetrahedron and left assuming crescent shape gradually. The hilum is more marked on its anterior surface and demarcates two areas into an upper smaller triangular area and a lower wider rectangular area. The base is deeply concave, fitting closely on the superomedial pole of the kidney. Its inferior border is oblique reaching upto the level of hilum. At 22 to 26 weeks the shapes of the suprarenals are more definite, the right as tetrahedron or pyramidal and left as crescentic (fig. 2). There is accelerated rate of growth of both suprarenals at this stage. Hilum is seen deeper than before on the anterior surface. The suprarenals look relatively smaller then the kidneys. There is displacement in position and a gradual shift away from the area of renal hilum towards the upper pole. innermost fetal zone by the end of second week, followed by completely established involution at the end of first month and lasts throughout the first year of life. It is succeeded by replacement with connective tissue which surrounds the medulla like a capsule and in the last stage the narrow strip of fibrous tissue between the cortex and medulla gradually disappears to attain adult appearance at 8th year of life. Materials & Methods: The material studied consisted of one hundred and two normal human fetuses, of different gestational ages ranging from 9 weeks to 40 weeks, collected from Department of Obstetrics and Gynaecology, RIMS Hospital, Imphal which were the products of medical termination of pregnancies and stillbirths. The age of the fetuses were calculated from the obstetrical history and crown-rump lengths. The fetuses were fixed in neutral buffered formalin for two weeks then dissection was carried out. Only those fetuses which were free from any gross anatomical abnormality were selected. The specimens were categorized into different groups. The suprarenals were studied in relation to the kidney and then removed. Gross observations regarding the shape, position, size in relation to the kidney, surfaces and hilum, length, breadth and weight of the suprarenal were recorded. After a thorough gross morphological study the suprarenals were subjected to histological processing and staining and the microscopic details were studied under low power (10X), high power (40X) and oil immersion (100X). Fig. 1 : Photograph of 15th weeks old fetus showing suprarenal gland (arrow) in situ with its respective kidney. Similar in shape of right and left both tongue shaped J. Anat. Soc. India 57 (1) 1-7 (2008) Fig. 2 : 2 Photograph of the suprarenal gland with kidneys of different age groups (12th weeks to 40th weeks) showing its changing chape

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