Adrenal Gland

The adrenal gland is a small but important gland that is part of the Endocrine System.  (It is also known as the suprarenal gland). It produces a variety of hormones including adrenaline and the steroids Aldosterone and Cortisol.

The adrenal gland is strongly involved in the function and regulation of stress. During times of stress, certain hormones are released.

This gland is located above each of the Kidneys.

The gland can be divided into two aspects:

1.) Adrenal Medulla
2.) Adrenal Cortex

Each Gland has an outer cortex (Adrenal Cortex) and an inner medulla Adrenal Medulla. The outer cortex is where the steroid hormones are produced.

Adrenal Medulla

This is the center or core of the adrenal gland. The other half, the adrenal cortex surrounds the medulla.

Chromaffin cells are specific cells that are found in the medulla and this is where “catecholamine” hormones are synthesized.

The two primary Catecholamines are:

–  Adrenaline (Epinephrine)
–  Noradrenaline (Norepinephrine)

These hormones are essential in the Nervous System.

The “flight-or-fight” response of the central nervous system is dependent on stress which can cause these hormones to become active. The Sympathetic Nervous system or “flight-or-fight” response is activated from fibers originating in the spinal cord.

Cortisol also helps receptors in the Medulla which triggers a series of reactions and results by increasing epinephrine synthesis and secretion.

The Adrenal Cortex

This is the outer layer of the adrenal gland. The cells in this region are designed to synthesize hormones referred to as “Corticosteroids“.

The Cortex is regulated or controlled by hormones produced in the brain. The Pituitary gland and the Hypothalamus trigger the Cortex. This can also be done by the renin-angiotensin system

The Three Main hormones produced are:

–  Cortisol
–  Corticosterone
–  Testosterone
–  Aldosterone

The cortex is divided into 3 regions:

1.)  Zona Glomerulosa
2.)  Zona Fasciluata
3.)  Zona Reticularis

Endocrine Disease involving dysfunction of the Adrenal Gland

1.)  Cushing’s Syndrome – Overproduction of Cortisol

2.)  Addison’s Disease – Insufficient Production of Cortisol

3.)  Congenital Adrenal Hyperplasia – Genetic Disorder/Disease where there is a dysregulation of endocrine control mechanisms.

4.)  Tumors

5.)  Others