Zona fasciculata

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Zona fasciculata
Gray1185.png
Layers of adrenaline gland.
Details
Identifiers
Latin zona fasciculata
MeSH D015383
FMA 69234
Anatomical terminology

The zona fasciculata (sometimes, fascicular or fasciculate zone) constitutes the middle and also the widest zone of the adrenal cortex, sitting directly beneath the zona glomerulosa . Constituent cells are organized into bundles or "fascicles".

Contents

The zona fasciculata chiefly produces glucocorticoids (mainly cortisol in humans), which regulate the metabolism of glucose. Glucocorticoid production is stimulated by adrenocorticotropic hormone (ACTH) [1] , which is released from the anterior pituitary, especially in times of stress as part of the fight-or-flight response. The zona fasciculata also generates a small amount of weak androgens (e.g., dehydroepiandrosterone). The main source of androgens will come from the zona reticularis region. In certain animals such as rodents, the lack of 17alpha-hydroxylase results in the synthesis of corticosterone instead of cortisol. [2]

Steroid-producing adrenal tumours and hyperplasia of the zona fasciculata result in excess cortisol production and are the cause for adrenal Cushing's syndrome. [1] The genetic disorder McCune–Albright syndrome can also present as Cushing's syndrome in affected patients.

Adrenal gland (zona fasciculata layer). Adrenal gland (zona fasiculata).JPG
Adrenal gland (zona fasciculata layer).

Related Research Articles

<span class="mw-page-title-main">Adrenal gland</span> Endocrine gland

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.

<span class="mw-page-title-main">Adrenocorticotropic hormone</span> Pituitary hormone

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 zona fasiculata and zona reticularis, respectively. ACTH is also related to the circadian rhythm in many organisms.

<span class="mw-page-title-main">Cushing's syndrome</span> Symptoms from excessive exposure to glucocorticoids such as cortisol

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 or loss of menses, with the exact mechanisms of why still unknown. Occasionally there may be changes in mood, headaches, and a chronic feeling of tiredness.

<span class="mw-page-title-main">Adrenal cortex</span> Cortex of the adrenal gland

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.

<span class="mw-page-title-main">Anterior pituitary</span> Anterior lobe of the pituitary gland

The anterior pituitary is a major organ of the endocrine system. The anterior pituitary is the glandular, anterior lobe that together with the makes up the pituitary gland (hypophysis) which, in humans, is located at the base of the brain, protruding off the bottom of the hypothalamus.

<span class="mw-page-title-main">Cortisol</span> Human natural glucocorticoid hormone

Cortisol is a steroid hormone in the glucocorticoid class of hormones and a stress hormone. When used as medication, it is known as hydrocortisone.

<span class="mw-page-title-main">Mineralocorticoid</span> Group of corticosteroids

Mineralocorticoids are a class of corticosteroids, which in turn are a class of steroid hormones. Mineralocorticoids are produced in the adrenal cortex and influence salt and water balances. The primary mineralocorticoid is aldosterone.

<span class="mw-page-title-main">Adrenal insufficiency</span> Insufficient production of steroid hormones by the adrenal glands

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.

Corticotropic cells, 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.

<span class="mw-page-title-main">Congenital adrenal hyperplasia due to 11β-hydroxylase deficiency</span> Medical condition

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.

<span class="mw-page-title-main">Zona reticularis</span> Layer of adrenal cortex

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.

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.

<span class="mw-page-title-main">Adrenocortical adenoma</span> Benign tumor of the adrenal gland

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.

Hypoadrenocorticism in dogs, or, as it is known in people, Addison's disease, is an endocrine system disorder that occurs when the adrenal glands fail to produce enough hormones for normal function. The adrenal glands secrete glucocorticoids such as cortisol and mineralocorticoids such as aldosterone; when proper amounts of these are not produced, the metabolic and electrolyte balance is upset. Mineralocorticoids control the amount of potassium, sodium, and water in the body. Hypoadrenocorticism is fatal if left untreated.

<span class="mw-page-title-main">Adrenal gland disorder</span> Medical condition

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.

<span class="mw-page-title-main">Antiglucocorticoid</span> Class of pharmaceutical drugs

Antiglucocorticoid drugs are a class of medications that act to reduce the effects of glucocorticoids, primarily cortisol, in the body. They include direct glucocorticoid receptor antagonists such as mifepristone and synthesis inhibitors such as metyrapone, ketoconazole, and aminoglutethimide. They are used to treat Cushing's syndrome.

<span class="mw-page-title-main">Generalized glucocorticoid resistance</span> Medical condition

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.

References

  1. 1 2 Seidel, Eric; Scholl, Ute I. (2016-06-27). "Intracellular Molecular Differences in Aldosterone- Compared to Cortisol-Secreting Adrenal Cortical Adenomas". Frontiers in Endocrinology. 7. Frontiers Media SA. doi: 10.3389/fendo.2016.00075 . ISSN   1664-2392.
  2. Nussdorfer, GG; Robba, C; Mazzochi, G; Rebuffat, P (March 1981). "Effects of angiotensin II on the zona fasciculata of the rat adrenal cortex: an ultrastructural stereologic study" (PDF). Journal of anatomy. 132 (Pt 2): 235–42. PMID   7275800.

See also