Die entwicklung der nebenniere beim schaf

The development of the adrenal gland of 80 embryos, fetuses or newborn sheep had been studied by light and electronmicroscopy.1.the anlage of the adrenal cortex appears in embryos with a crown-rump length (CRL) of 13 mm (correspondingt.o the 2’jt.h d.a~ Qf l)l:e~Gl\.();Y) ~ ali) an. il\ .. ~a’i!,il\ati<;)l\ <;)1:the coelomic epithelium, ventro-lateral of the aorta and eaia1. of tne me13’one’Pnro13. A second ’Proliferation of tne coelomic epithelium towards the primordium of the adrena2.At 24 mm CRL (35 days) sympatho-chromaffinoblasts immigratefrom the sympathetic anlage and invade the anlage of the adrenal cortex.3.At 30 mm CRL (36 days) a fibrous capsule begins to develop around the anlage of the adrenal gland.4.At 55 mm CRL (45 days) for the first time a positivechromaffine reaction of the medullary cells in the centerof the organ occurs.5.Between 105 and 120 mm CRL (60 - 65 days) the adrenalcortex begins to differentiate from the periphery into the zona multiformis and the zona fasciculata at thesame time. The cells of the zona multiformis increase in size, the cytoplasm becomes pale and contains large lipid ’ DROPlets which are recognizable even by light microscopy.