The three layers of the adrenal cortex are: Microscopic view of the adrenal cortex: The layers of the adrenal gland cortex, zona glomerulosa ZG , fasciculata ZF , and reticularis ZR , responsible to produce aldosterone, cortisol, and sex steroid hormone. The zona glomerulosa ZG is the most superficial layer of the adrenal cortex and it produces the hormone aldosterone as well as some small amounts of progesterone a sex hormone.
The mineralocorticoid aldosterone is produced here. The zona fasciculata ZF is the middle zone of the adrenal cortex, and it primarily produces cortisol. The zona reticularis ZR is the inner most zone of the adrenal cortex and it is adjacent to the adrenal medulla. Functions of the zona retularis are to store cholesterol for steroidogenesis the making of steroid hormones and the secretion of sex hormones such as estrogen, and testosterone in small amounts.
Technical Information for Doctors and Nurses. In the zona glomerulosa ZG , progesterone is converted through several steps to the mineralocorticoid aldosterone. In the other layers of the cortex, progesterone is converted first to hydroxyprogesterone and then to either the hydroxysteroid cortisol or the ketosteroid sex hormones.
The mineralocorticoid aldosterone is produced in the outermost layer of the adrenal cortex, the zona glomerulosa. Aldosterone secretion is primarily controlled through a renal pathway. Decreased arterial pressure or decreased serum sodium concentration is sensed by the juxtaglomerular apparatus and the macula densa, respectively. The result is the production and release of renin, activating angiotensin I. Circulating angiotensin II stimulates aldosterone secretion.
To a lesser degree, aldosterone secretion is stimulated by direct effects of ACTH and elevated serum potassium. With aging, there is decreased production of aldosterone. The zona fasciculata ZF and zona reticularis ZR are responsible for glucocorticoid production. Secretion of cortisol is controlled via the hypothalamic-pituitary-adrenal HPA axis. Hypothalamic corticotropin-releasing hormone CRH causes release of adrenocorticotrophic hormone ACTH from the anterior pituitary gland, which stimulates the adrenal cortex to release cortisol.
ACTH has a plasma half-life of 25 minutes and cortisol has a plasma half-life of 90 minutes. ACTH and cortisol production is constant over life in normal, unstressed individuals. Adrenal androgen release is regulated by ACTH, whereas gonadal release of testosterone and estrogen are under a separate pathway of pituitary-gonadotrophic control.
Androgen production peaks at puberty and progressively declines with advancing age. Stimulation of the adrenal medulla is via preganglionic sympathetic fibers causing release of dopamine, norepinephrine and epinephrine.
Cushing's syndrome is due to overactive adrenal glands from excessive production of cortisol. The clinical findings include thinning and bruising of the skin, obesity , diabetes , psychiatric disturbances, high blood pressure, muscle weakness, osteoporosis , excessive facial hair and irregular periods in women.
It can result in growth failure in children. Patients with cortisol excess also have impaired wound healing and an increased susceptibility to infection. Addison's disease or adrenal insufficiency is due to underactive adrenal glands associated with lack of hormones. Adrenal insufficiency may be acute or chronic.
Symptoms of chronic adrenal insufficiency include low blood pressure, fatigue, weight loss, anorexia, nausea, vomiting, abdominal pain, salt craving and low blood sugar. Skin and mucous membranes may show increased pigmentation. The loss of secondary sex characteristics is seen only in women with the disease. Acute adrenal insufficiency is a medical emergency and must be identified and promptly treated. The hallmarks of acute adrenal insufficiency are circulatory collapse with abdominal pain and low blood sugar.
Overproduction of androgens is also very rare but may result in excessive hair growth and menstrual period disturbances. Tumours of the adrenal gland are mostly benign and do not result in over or underproduction of adrenal hormones. Most tumours are discovered incidentally when people undergo scans for various other reasons. Adrenal cancer is very rare. Adrenal tumours may require surgery if they are large or overproduce hormones. The treatment of each disorder varies according to the specific cause.
Patients with any concerns about these conditions should seek advice from their doctor. Hormone replacement therapy or HRT also known as menopausal hormone therapy; MHT is the replacement of female sex hormones oestrogen and progesterone in women to control symptoms of the menopause. About Contact Events News. Health care providers use different tests to check for adrenal disorders depending on your symptoms and health history.
For example, you may have tests of your blood, urine pee , or saliva spit. These tests check your hormone levels. Different types of adrenal gland disorders have different treatments. They include medicines and surgery. Radiation therapy is sometimes a treatment for tumors. There are treatments to cure certain adrenal gland disorders. For other disorders, treatments can manage your symptoms. The information on this site should not be used as a substitute for professional medical care or advice.
Contact a health care provider if you have questions about your health. Adrenal Gland Disorders. See, Play and Learn No links available. Research Clinical Trials Journal Articles. Resources Reference Desk Find an Expert. What are adrenal glands? All of these hormones do many important jobs, including Turning food into energy and managing blood sugar levels Balancing salt and water Keeping blood pressure normal Responding to illness and stress your "fight or flight" response Timing when and how fast a child develops sexually Supporting pregnancy What are adrenal gland disorders?
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