What are the adrenal glands?

The adrenal glands are two small endocrine glands, located on the top of the kidneys. Together they weigh around 8-10 grams. Each consists of 2 parts: the cortex on the outside and the medulla in the centre, each having different functions, hormonal production and embryological origins. However, they are in perfect harmony with each other and together with the hypothalamus and pituitary gland they form the hypothalamic-pituitary-adrenal axis that makes up, together with the sympathetic nervous system, the stress system.

The adrenal cortex is derived from the mesoderm and produces a range of steroid hormones, the most important of which are: cortisol, which has a wide range of functions, from the stress response and sugar regulation to the induction of appetite and emotional balance, aldosterone, which regulates the blood pressure, and adrenal androgens, which are an important source of androgens, especially in women and children.

The adrenal medulla is part of the autonomic/sympathetic nervous system and therefore has neuroendocrine origins. It secretes catecholamines (adrenaline, noradrenaline, dopamine), which are also involved in the stress response by increasing the heart rate and blood pressure.