- What is the adrenal gland?
- What is the function of the adrenal gland?
- Where is the adrenal gland?
- What problems can the adrenal gland cause?
The adrenal is a paired organ sitting on the upper pole of both kidneys. It is a hormone gland divided into two parts - the adrenal medulla and the adrenal cortex. They produce different hormones like the stress hormone epinephrine (in the pith). Read here everything important about the adrenals: Function, anatomy and important diseases!
What is the adrenal gland?
The adrenals are a paired organ that produces a variety of hormones. It is about three inches long, one and a half inches wide and weighs about five to fifteen grams. Each adrenal gland is divided into two parts: adrenal medulla and cortex.
Here inside the organ important adrenal hormones from the group of so-called catecholamines are produced and released into the blood:
- Epinephrine: astringent (constricting) on blood vessels, increases heart rate and blood pressure;
- Norepinephrine: also has a constrictive effect on the vessels, but slows the heart rate and increases the blood flow to the heart;
- Dopamine: precursor of the two catecholamines mentioned above, but also acts as a hormone itself; has numerous effects (influences the mood, increases the blood circulation of the abdominal organs, etc.)
Adrenal medulla cells stain well with chromium salts. For this reason they are called "chromaffin cells". Other components of the medulla are connective tissue, blood vessels and nerve fibers.
Hormones are also produced in the bark area (aldosterone, cortisol, androgens = male sex hormones). Read more about it in the post adrenal cortex.
What is the function of the adrenal gland?
The function of the paired organ is the production and release of various vital hormones.
The adrenal medulla expresses epinephrine and norepinephrine, two "stress hormones". These are stored in small granules and are released into the blood in stress and alarm situations - whenever it is important to have as much energy as possible in a short time in order to either escape or fight. This energy is provided by the body in the form of sugar.
The release of catecholamines is promoted by acetylcholine, a messenger substance of the nervous system. Epinephrine and norepinephrine increase heart rate and blood pressure, accelerate breathing, dilate the airways and allow the muscles to tense up and react quickly. At the same time, systems that are not needed at these moments (such as the gastrointestinal tract) are shut down.
Where is the adrenal gland?
An adrenal gland is located on each upper pole of the kidney. The left is crescent-shaped, the right triangular.
What problems can the adrenal gland cause?
There are numerous adrenal diseases:
A phaeochromocytoma is a benign adrenal medullary tumor that secretes epinephrine and norepinephrine, as well as the precursor dopamine in immature tumor forms (pheochromoblastoma, neuroblastoma). Patients suffer from seizure-like hypertension, headache, sweating, and have pale skin (because adrenaline and norepinephrine constrict blood vessels).
Enlargement or benign or malignant adrenal tumors can lead to overproduction of the hormone aldosterone (in the bark area). Physicians then speak of the so-called Conn syndrome. Those affected have a difficult to set high blood pressure.
If too much cortisol is produced due to a kidney tumor, Cushing's syndrome develops. Typical symptoms are trunk fatness, full moon face, muscle weakness and hypertension.
In a bovine dysfunction, too few hormones (aldosterone, cortisol, androgens) are produced. It develops Addison's disease (Addison's disease). Symptoms include browning of the skin, tiredness, poor appetite and weight loss, hunger for salty foods, low blood pressure, indigestion such as nausea and vomiting, and mental symptoms such as depression and irritability. Addison's disease leads to death if left untreated.
In adrenogenital syndrome (AGS), too little cortisol and aldosterone and too much androgen are produced due to an enzyme defect. The affected infants are tired and apathetic. Due to the excess of male sex hormones, the clitoris or penis and testicles are enlarged. The girls masculinize, puberty occurs prematurely.
The marrow region of adrenal rarely has a hypofunction.