The adrenal glands are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is divided into three main zones: the zona glomerulosa, the zona fasciculata and the zona reticularis.
Adrenocorticotropic hormone is a polypeptide tropic hormone produced by and secreted by the anterior pituitary gland. It is also used as a medication and diagnostic agent. ACTH is an important component of the hypothalamic-pituitary-adrenal axis and is often produced in response to biological stress. Its principal effects are increased production and release of cortisol and androgens by the cortex and medulla of the adrenal gland, respectively. ACTH is also related to the circadian rhythm in many organisms.
Cushing's syndrome is a collection of signs and symptoms due to prolonged exposure to glucocorticoids such as cortisol. Signs and symptoms may include high blood pressure, abdominal obesity but with thin arms and legs, reddish stretch marks, a round red face due to facial plethora, a fat lump between the shoulders, weak muscles, weak bones, acne, and fragile skin that heals poorly. Women may have more hair and irregular menstruation. Occasionally there may be changes in mood, headaches, and a chronic feeling of tiredness.
Cortisone is a pregnene (21-carbon) steroid hormone. It is a naturally-occurring corticosteroid metabolite that is also used as a pharmaceutical prodrug. Cortisol is converted by the action of the enzyme corticosteroid 11-beta-dehydrogenase isozyme 2 into the inactive metabolite cortisone, particularly in the kidneys. This is done by oxidizing the alcohol group at carbon 11. Cortisone is converted back to the active steroid cortisol by stereospecific hydrogenation at carbon 11 by the enzyme 11β-Hydroxysteroid dehydrogenase type 1, particularly in the liver.
The adrenal cortex is the outer region and also the largest part of the adrenal gland. It is divided into three separate zones: zona glomerulosa, zona fasciculata and zona reticularis. Each zone is responsible for producing specific hormones. It is also a secondary site of androgen synthesis.
Cortisol is a steroid hormone, in the glucocorticoid class of hormones and a stress hormone. When used as a medication, it is known as hydrocortisone.
Adrenal insufficiency is a condition in which the adrenal glands do not produce adequate amounts of steroid hormones. The adrenal glands—also referred to as the adrenal cortex—normally secrete glucocorticoids, mineralocorticoids, and androgens. These hormones are important in regulating blood pressure, electrolytes, and metabolism as a whole. Deficiency of these hormones leads to symptoms ranging from abdominal pain, vomiting, muscle weakness and fatigue, low blood pressure, depression, mood and personality changes to organ failure and shock. Adrenal crisis may occur if a person having adrenal insufficiency experiences stresses, such as an accident, injury, surgery, or severe infection; this is a life-threatening medical condition resulting from severe deficiency of cortisol in the body. Death may quickly follow.
Corticotropes are basophilic cells in the anterior pituitary that produce pro-opiomelanocortin (POMC) which undergoes cleavage to adrenocorticotropin (ACTH), β-lipotropin (β-LPH), and melanocyte-stimulating hormone (MSH). These cells are stimulated by corticotropin releasing hormone (CRH) and make up 15–20% of the cells in the anterior pituitary. The release of ACTH from the corticotropic cells is controlled by CRH, which is formed in the cell bodies of parvocellular neurosecretory cells within the paraventricular nucleus of the hypothalamus and passes to the corticotropes in the anterior pituitary via the hypophyseal portal system. Adrenocorticotropin hormone stimulates the adrenal cortex to release glucocorticoids and plays an important role in the stress response.
Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency is a form of congenital adrenal hyperplasia (CAH) which produces a higher than normal amount of androgen, resulting from a defect in the gene encoding the enzyme steroid 11β-hydroxylase (11β-OH) which mediates the final step of cortisol synthesis in the adrenal. 11β-OH CAH results in hypertension due to excessive mineralocorticoid effects. It also causes excessive androgen production both before and after birth and can virilize a genetically female fetus or a child of either sex.
Congenital adrenal hyperplasia due to 17α-hydroxylase deficiency is an uncommon form of congenital adrenal hyperplasia (CAH) resulting from a mutation in the gene CYP17A1, which produces the enzyme 17α-hydroxylase. It causes decreased synthesis of cortisol and sex hormones, with resulting increase in mineralocorticoid production. Thus, common symptoms include mild cortisol deficiency, ambiguous genitalia in men or amenorrhea at puberty in women, and hypokalemic hypertension. However, partial (incomplete) deficiency often has inconsistent symptoms between patients, and affected women may be asymptomatic except for infertility.
The zona reticularis is the innermost layer of the adrenal cortex, lying deep to the zona fasciculata and superficial to the adrenal medulla. The cells are arranged cords that project in different directions giving a net-like appearance.
11β-Hydroxysteroid dehydrogenase enzymes catalyze the conversion of inert 11 keto-products (cortisone) to active cortisol, or vice versa, thus regulating the access of glucocorticoids to the steroid receptors.
Adrenalectomy is the surgical removal of one or both adrenal glands. It is usually done to remove tumors of the adrenal glands that are producing excess hormones or is large in size. Adrenalectomy can also be done to remove a cancerous tumor of the adrenal glands, or cancer that has spread from another location, such as the kidney or lung. Adrenalectomy is not performed on those who have severe coagulopathy or whose heart and lungs are too weak to undergo surgery. The procedure can be performed using an open incision (laparotomy) or minimally invasive laparoscopic or robot-assisted techniques. Minimally invasive techniques are increasingly the gold standard of care due to shorter length of stay in the hospital, lower blood loss, and similar complication rates.
In humans and other animals, the adrenocortical hormones are hormones produced by the adrenal cortex, the outer region of the adrenal gland. These polycyclic steroid hormones have a variety of roles that are crucial for the body's response to stress, and they also regulate other functions in the body. Threats to homeostasis, such as injury, chemical imbalances, infection, or psychological stress, can initiate a stress response. Examples of adrenocortical hormones that are involved in the stress response are aldosterone and cortisol. These hormones also function in regulating the conservation of water by the kidneys and glucose metabolism, respectively.
In the human endocrine system, a spongiocyte is a cell in the zona fasciculata of the adrenal cortex containing lipid droplets that show pronounced vacuolization, due to the way the cells are prepared for microscopic examination.
An adrenocortical adenoma or adrenal adenoma is commonly described as a benign neoplasm emerging from the cells that comprise the adrenal cortex. Like most adenomas, the adrenocortical adenoma is considered a benign tumor since the majority of them are non-functioning and asymptomatic. Adrenocortical adenomas are classified as ACTH-independent disorders, and are commonly associated with conditions linked to hyperadrenalism such as Cushing's syndrome (hypercortisolism) or Conn's syndrome (hyperaldosteronism), which is also known as primary aldosteronism. In addition, recent case reports further support the affiliation of adrenocortical adenomas with hyperandrogenism or florid hyperandrogenism which can cause hyperandrogenic hirsutism in females. "Cushing's syndrome" differs from the "Cushing's disease" even though both conditions are induced by hypercortisolism. The term "Cushing's disease" refers specifically to "secondary hypercortisolism" classified as "ACTH-dependent Cushing's syndrome" caused by pituitary adenomas. In contrast, "Cushing's syndrome" refers specifically to "primary hypercortisolism" classified as "ACTH-independent Cushing's syndrome" caused by adrenocortical adenomas.
Adrenal gland disorders are conditions that interfere with the normal functioning of the adrenal glands. Your body produces too much or too little of one or more hormones when you have an adrenal gland dysfunction. The type of issue you have and the degree to which it affects your body's hormone levels determine the symptoms.
Glucocorticoid remediable aldosteronism also describable as aldosterone synthase hyperactivity, is an autosomal dominant disorder in which the increase in aldosterone secretion produced by ACTH is no longer transient.
Generalized glucocorticoid resistance or Chrousos syndrome is a rare genetic disorder that can run in families or be sporadic. It is characterized by partial or generalized target-tissue insensitivity to glucocorticoids.
Adrenalism describes the condition of an excessive or substandard secretion of hormones related to the adrenal glands, which are found directly superior to the kidneys. Adrenalism can be further distinguished as hyperadrenalism, referring to the excessive secretion of hormones, and hypoadrenalism, referring to the insufficient secretion of hormones.
