The human adrenal cortex: ultrastructure and base-line morphometric data.

The morphology of the human adult female adrenal cortex was studied by electron microscopy and morphometry. Zona glomerulosa contains outer undifferentiated small cells and inner well-differentiated larger elements, which display mitochondria with tubulo-laminar cristae, abundant smooth endoplasmic reticulum (SER) and sparse lipid droplets. Zona fasciculata cells possess typical mitochondria with vesicular cristae, a well-developed SER, lipid droplets and some lipofuscin-pigment granules, which increase in number in the cells of the inner portion of the zone. Sometimes lipid-laden cells can be observed in the zona fasciculata. Zona reticularis cells have the same morphological features as the zona fasciculata elements, but display a striking rise in the number of lipofuscin-pigment granules.