The adrenal gland is situated on top of each one of the kidneys. They weigh 8-10g in weight and there is one on each side of each kidney. The Adrenal Gland produces a number of hormones such as epinephrine. There are three main areas of the adrenal gland, the Medulla, Cortex and Capsule. The capsule surrounds the adrenal gland and gives strength. The cortex can be seperated into three sections; the Zona glomerulosa, the Zona fasciculata and the Zona reticularis. The medulla is the site of synthesis of epinephrine and different zones of the cortex produce different steroids.
The Zona glomerulosa is the outer layer of the cortex; there is a lack of 17 alpha hydroxylase here meaning that the Zona glomerulosa produces aldosterone.
The Zona fasiculata and the Zona reticularis are the middle and innermost layers of the cortex. They both produce cortisol and androgens.
Hormones are not stored in vesicles, they are made on demand as the cortex is very rich in mitochondria