Index
Also called adrenal glands, they are small structures attached to the upper part of each kidney.
The human body has two adrenal glands that release chemicals called hormones into the bloodstream. These hormones affect many parts of the human body.
Where are the adrenal glands?
The human body has two adrenal glands, and one sits on top of each kidney. Each adrenal gland weighs 4-5 g in an adult. The adrenal glands are detected at six weeks of gestation for the first time.
Function
Each adrenal gland comprises two distinct parts: the outer part called the adrenal cortex and the internal suprarenal medulla.
The adrenal glands secrete different hormones that act as “chemical messengers.” These hormones travel in the bloodstream and work on various body tissues to allow them to function correctly. All adrenocortical hormones are steroidal compounds made of cholesterol.
What hormones do the adrenal glands produce?
The adrenal cortex produces three hormones:
Mineralocorticoids: The most important of which is aldosterone. This hormone helps maintain the body’s salt and water levels, which, in turn, regulate blood pressure. Without aldosterone, the kidney loses excessive salt (sodium) and water, leading to severe dehydration and low blood pressure.
Glucocorticoids: Predominantly cortisol. This hormone responds to the disease and helps regulate the body’s metabolism.
Cortisol stimulates glucose production by helping the body release the necessary storage ingredients (fat and muscle) to produce glucose. Cortisol also has significant anti-inflammatory effects.
Adrenal androgens: Male sex hormones, mainly dehydroepiandrosterone (DHEA) and testosterone. All have weak effects, but they play a role in the early development of male sexual organs in childhood and female body hair during puberty.
Adrenocorticotropic hormone (ACTH), secreted by the anterior pituitary gland, mainly affects the release of glucocorticoids and adrenal androgens by the adrenal gland and, to a much lesser extent, also stimulates the release of aldosterone.
The adrenal medulla produces catecholamines: Catecholamines include adrenaline, noradrenaline, and small amounts of dopamine; These hormones are responsible for all the physiological characteristics of the stress response, the so-called “fight or flight” response.
Affections of the adrenal gland
Commonly, an overproduction of aldosterone, which causes a condition known as primary hyperaldosteronism, may occur. This causes high blood pressure, which is resistant to conventional blood pressure control tablets and salt disorders.
High blood pressure can cause headaches and visual problems. Some studies have suggested that hyperaldosteronism can account for up to 5% of all people with high blood pressure and an even higher proportion of those who have treatment-resistant hypertension.
In rare cases, the adrenal glands can become overactive or inactive. Cushing’s syndrome and Addison’s disease are the two central glucocorticoid-related disorders that result from these.
Cushing’s syndrome: is due to overactive adrenal glands due to excessive production of cortisol.
Clinical findings include thinning and bruising of the skin, obesity, diabetes, psychiatric disorders, high blood pressure, muscle weakness, osteoporosis, excessive facial hair, and irregular periods in women. It can fail growth in children.
Patients with excess cortisol also have healing problems and increased susceptibility to infection.
Addison’s disease or adrenal insufficiency is due to the shortage of the adrenal glands associated with the lack of hormones.
Adrenal insufficiency can be acute or chronic. Symptoms of chronic adrenal insufficiency include low blood pressure, fatigue, weight loss, anorexia, nausea, vomiting, abdominal pain, cravings for salt, and low blood sugar.
The skin and mucous membranes may show increased pigmentation. The loss of secondary sexual characteristics is only observed in women with the disease.
Acute adrenal insufficiency is a medical emergency and must be identified and treated promptly. The characteristics of acute adrenal insufficiency are circulatory collapse with abdominal pain and low blood sugar.
The overproduction of androgens is also very rare, but it can cause excessive hair growth and alterations in the menstrual period.
The adrenal gland tumors are primarily benign and do not produce excessive or insufficient production of adrenal hormones.
Most tumors are discovered incidentally when people undergo scanning for several other reasons. Adrenal cancer is sporadic. Adrenal tumors may require surgery if they are large or overproduce hormones.
