Fig. 7.1 
Histological section of an adrenal gland.
 The medulla represents ten per cent of the gland, while the remaining ninety per cent is made up of cortical tissue – the zonae glomenulosa, fasciculata, and reticulans. The whole gland is surrounded by a fibrous capsule below which the zona glomenulosa cells appear only focally. Haematoxylin and eosin stain, magnification x 250.