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Adrenal Cortex - Functions & Details

Adrenal Cortex - Functions & Details

Edited By Irshad Anwar | Updated on Jul 02, 2025 05:14 PM IST

Hormones play a very important role in the growth and development of the human body. They are also responsible for certain functions in the body. Adrenal Gland is also important as it releases certain important hormones. Adrenal Cortex is one of the important topics of Biology which carries weightage of 2-3% in NEET and 4-5% in CBSE and other Paramedical Exams.

This Story also Contains
  1. What Is Adrenal Cortex?
  2. Anatomy Of The Adrenal Cortex
  3. Functions Of The Adrenal Cortex
  4. Hormonal Regulation And Feedback Mechanisms
  5. Disorders Of The Adrenal Cortex
  6. Diagnostic Techniques
  7. Tips, Tricks, and Strategies for Adrenal Cortex
  8. Types of Questions Asked from Adrenal Cortex

What Is Adrenal Cortex?

The adrenal glands are small organs that sit atop each kidney yet play a crucial role in the body's response to stress and homeostasis. These glands are divided into two portions: the adrenal medulla and the adrenal cortex. The adrenal cortex is, in particular, crucial, being an outer region that secretes a variety of hormones controlling metabolism, immune response, blood pressure, and many others related to the essential activities of living. Shortly, it means that if there is a functional failure, the balance would be impossible to maintain, and the body could not react within and without the stressors.

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Anatomy Of The Adrenal Cortex

The adrenal glands are anatomically located and structured for their essential functions:

  • This position, sitting on top of each kidney, allows for the glands to secrete hormones directly into the bloodstream.

  • Each adrenal gland has an outer cortex and an inner medulla.

  • The cortex itself can be divided into three layers, each performing the production of different forms of hormones.

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The adrenal cortex includes three distinct layers:

Zona glomerulosa

  • The outermost layer of the adrenal cortex.

  • Mainly responsible for the production of the mineralocorticoids, such as aldosterone.

  • Maintains the balance between the levels of sodium and potassium, important in maintaining blood pressure and fluid balance.

Zona fasciculata

  • The middle layer of the adrenal cortex.

  • Producing glucocorticoids; primarily cortisol.

  • Managing the responses to stress, metabolism, and immune system function.

Zona reticularis

  • The innermost layer of the adrenal cortex.

  • Producing androgens, including dehydroepiandrosterone (DHEA).

  • Contributing to the development of secondary sexual characteristics and overall energy levels.

Functions Of The Adrenal Cortex

Each layer of the adrenal cortex produces certain hormones crucial in different bodily functions:

Zona glomerulosa

  • Hormone Produced: Mineralocorticoids (Aldosterone)

  • Controls sodium and potassium levels in the blood, thereby affecting blood pressure and fluid balance.

Zona fasciculata

  • Hormone Produced: Glucocorticoids (Cortisol)

  • Inside this layer, metabolism is regulated by the turning of lipids, proteins and carbohydrates into energy.

  • Glucocorticoids are concerned with the regulation of the response to stressful and inflammatory stimuli.

Zona reticularis

  • Hormone Produced: Androgens (DHEA)

  • Affects secondary sex characteristics, and contributes to libido and overall energy and muscle mass.

Hormonal Regulation And Feedback Mechanisms

The production and regulation of hormones produced by the adrenal cortex involve complex feedback mechanisms

Role of ACTH

  • Produced by the pituitary gland.

  • Stimulates the adrenal cortex to produce cortisol.

  • ACTH levels are regulated by the hypothalamus through the release of corticotropin-releasing hormone.

Negative Feedback Mechanism

  • High levels of cortisol first inhibit the release of CRH and later of ACTH, hence decreasing the production of cortisol.

  • Maintains the balance of the hormones and prevents excess production of cortisol.

Disorders Of The Adrenal Cortex

The disorders of the adrenal cortex result from an over- or underproduction of hormones. This includes:

Hyperfunction Conditions

  • Cushing's syndrome: This is caused by excessive production of cortisol and manifests itself in patients through weight gain, hypertension, and skin changes.

  • Hyperaldosteronism: Excessive production of aldosterone results in the patient complaining about high blood pressure and low potassium levels.

  • Adrenogenital syndrome: This follows from excessive androgen production.

Hypofunction Conditions

  • Addison's disease: This occurs when there is insufficient production of cortisol and aldosterone.

  • The symptoms include fatigue, weight loss, and reduced blood pressure.

Diagnostic Techniques

The following diagnostic tests are used to diagnose and monitor the condition of patients with disorders in the adrenal cortex:

Hormone Level Blood Tests

  • Measure the levels of cortisol, aldosterone, and androgens to determine any imbalance.

  • ACTH stimulation test, 24-hour urinary free cortisol test.

Imaging Studies

  • CT (Computed Tomography) scans and MRI (Magnetic Resonance Imaging).

  • Visualise the adrenal glands to identify any anatomical abnormalities like tumours.

Stimulation and Suppression Tests

  • Stimulation Tests: Monitor the response of the adrenal gland to synthetic ACTH.

  • Suppression Tests: Calculate the amount of cortisol produced by the adrenal gland by administering dexamethasone and then measuring the level of cortisol produced subsequently.

Conclusion

Understanding the anatomy, physiology, and disorders of the adrenal cortex is thus very important in diagnosing and treating related conditions. The normal functioning of the adrenal cortex maintains the balance of the various hormones produced and is the key to health; therefore, updated research and awareness are significant in the field.

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Tips, Tricks, and Strategies for Adrenal Cortex

It takes effort to remember everything in a single go. We made the entire problem easy. Some of the tricks regarding Adrenal Cortex are given below which you can use to memorise the important points.

Hormones of the Adrenal Cortex

"AMC: Aldosterone, Mineralocorticoids, Cortisol"

  • A: Aldosterone

  • M: Mineralocorticoids

  • C: Cortisol

Functions of Cortisol

"SMIB: Stress, Metabolism, Immune, Blood sugar"

  • S: Stress response

  • M: Metabolism regulation

  • I: Immune suppression

  • B: Blood sugar control

Aldosterone Regulation

"RAA: Renin-Angiotensin-Aldosterone"

  • R: Renin

  • A: Angiotensin

  • A: Aldosterone

Disorders of the Adrenal Cortex

"ACC: Addison’s, Cushing’s, Conn’s"

  • A: Addison’s disease

  • C: Cushing’s syndrome

  • C: Conn’s syndrome

Layers of the Adrenal Cortex

"GFR: Glomerulosa, Fasciculata, Reticularis"

  • G: Zona Glomerulosa

  • F: Zona fasciculata

  • R: Zona Reticularis

Types of Questions Asked from Adrenal Cortex

During the preparation of the exam, there are different types of questions asked about Adrenal Cortex in different forms. The table given below contains the different patterns of questions asked in different exams.

Exam Type

Types of Questions Asked

Weightage

CBSE

  • Structure and function of the adrenal cortex.

  • Hormones secreted by the adrenal cortex (glucocorticoids, mineralocorticoids, androgens).

  • Regulation of cortisol and aldosterone.

  • Disorders related to the adrenal cortex (e.g., Addison’s disease, Cushing’s syndrome).

4%

NEET

  • Hormonal control of metabolism by adrenal cortex (cortisol, aldosterone).

  • Feedback mechanisms in adrenal hormone regulation.

  • Effects of adrenal cortex hormones on stress response.

  • Adrenal disorders (e.g., hypo- and hypersecretion conditions).

2-4%

Paramedical

  • Clinical significance of adrenal hormones in stress and metabolism.

  • Diagnostic methods for adrenal cortex disorders.

  • Role of adrenal cortex in electrolyte balance and blood pressure regulation.

  • Hormonal therapies for adrenal insufficiencies.

3%

Frequently Asked Questions (FAQs)

1. When does the adrenal cortex develop?

The adrenal cortex develops in the early weeks of gestation. At this period, the adrenal gland has two sections, such as the foetal and adult definitive zones. This foetal layer compresses and disappears when we are born. The developing gland is mainly responsible for producing adrenal cortex hormones and connects to nerves nearby.

2. What are the disorders that affect the adrenal cortex?

The disorders that affect the adrenal cortex are:

  • Adrenal tumours

  • Addison's disease

  • Adrenocortical carcinoma

  • Hyperaldosteronism

  • Congenital adrenal hyperplasia

  • Hypercortisolism

  • Conn’s syndrome

3. What are the treatments for adrenal cortex disorders?

The treatments available for adrenal cortex diseases are:

  • Change in lifestyle - Practising healthy habits can reduce stress and strain on the adrenal glands.

  • Hormone replacement therapy - This is the case in which the identical hormone is replaced to restore the proper functioning of hormones to a satisfactory level.

  • Medication - If the body is producing more hormones than it needs, then medication such as drugs and medicines, is used to avoid that.

  • Tumour and cancer treatments - This treatment is used to remove the tumours that are producing the high hormones.

Plastic surgery - This treatment repairs the structures affected by the excess hormonal levels.

4. Where is the adrenal cortex located in our body?

The adrenal cortex is a part of the adrenal gland. It is located on top of the right and left kidneys. This is mainly used for producing the hormones that are responsible for the proper functioning of organs.

5. How can we take care of the adrenal cortex?

We have to take good care of the adrenal cortex in the following ways:

  • Taking food that is rich in nutrients

  • Following a healthy lifestyle

  • Doing meditation and yoga daily

  • Taking prevention by practising regular checkups

6. What is the adrenal cortex and where is it located?
The adrenal cortex is the outer layer of the adrenal gland, which sits on top of each kidney. It's responsible for producing several important hormones that regulate various bodily functions.
7. How does the structure of the adrenal cortex relate to its function?
The adrenal cortex is divided into three distinct zones, each producing different hormones: the zona glomerulosa (outermost), zona fasciculata (middle), and zona reticularis (innermost). This structural organization allows for the efficient production of specific hormones in each zone.
8. What is the significance of the zona reticularis in adrenal androgen production?
The zona reticularis is the innermost layer of the adrenal cortex and is primarily responsible for producing adrenal androgens like DHEA and androstenedione. These hormones are particularly important during adrenarche (adrenal maturation) in childhood.
9. How do adrenal cortex hormones affect water balance in the body?
Aldosterone, produced in the adrenal cortex, plays a crucial role in water balance by promoting sodium reabsorption in the kidneys. This leads to water retention, helping to maintain blood volume and pressure.
10. What is the relationship between the adrenal cortex and the reproductive system?
The adrenal cortex produces small amounts of sex hormones (androgens and estrogens). In women, these adrenal androgens can be significant contributors to overall androgen levels. Additionally, excessive cortisol can interfere with reproductive function in both sexes.
11. What is adrenal hyperplasia and how does it differ from adrenal hypertrophy?
Adrenal hyperplasia refers to an increase in the number of cells in the adrenal cortex, while adrenal hypertrophy refers to an increase in the size of existing cells. Both can result in enlarged adrenal glands but occur through different cellular mechanisms.
12. How do adrenal cortex hormones affect bone metabolism?
Glucocorticoids like cortisol can have negative effects on bone metabolism when present in excess. They inhibit bone formation by suppressing osteoblast activity and increase bone resorption, potentially leading to osteoporosis with long-term exposure.
13. How do adrenal cortex hormones influence lipid metabolism?
Cortisol promotes lipolysis (breakdown of fat) in adipose tissue, releasing fatty acids into the bloodstream. It also stimulates fat redistribution, which can lead to characteristic fat deposits in conditions like Cushing's syndrome.
14. How does the adrenal cortex respond to acute vs. chronic stress?
In acute stress, the adrenal cortex rapidly increases cortisol production to help the body cope. In chronic stress, there's sustained activation of the HPA axis, which can lead to dysregulation of cortisol production and potentially adrenal fatigue over time.
15. How does the circadian rhythm influence cortisol production?
Cortisol production follows a circadian rhythm, with levels highest in the early morning and lowest at night. This rhythm is controlled by the suprachiasmatic nucleus in the brain, which regulates the release of CRH and ACTH throughout the day.
16. What is Addison's disease and how does it relate to the adrenal cortex?
Addison's disease is a condition where the adrenal cortex doesn't produce enough hormones, particularly cortisol and aldosterone. This can result from autoimmune destruction of the adrenal cortex or other causes of adrenal insufficiency.
17. How does Cushing's syndrome affect the body, and what's its relationship to the adrenal cortex?
Cushing's syndrome results from excessive cortisol in the body, which can be caused by overproduction in the adrenal cortex or by taking glucocorticoid medications. Symptoms include weight gain, thinning skin, easy bruising, and muscle weakness.
18. What is congenital adrenal hyperplasia (CAH) and how does it affect adrenal cortex function?
CAH is a group of genetic disorders affecting enzyme production in the adrenal cortex. This leads to imbalances in hormone production, often resulting in decreased cortisol and increased androgen levels, which can cause various symptoms depending on the specific enzyme deficiency.
19. How does chronic stress affect the function of the adrenal cortex?
Chronic stress can lead to prolonged activation of the HPA axis, resulting in sustained high levels of cortisol. Over time, this can lead to dysregulation of the axis, potentially causing problems like adrenal fatigue or resistance to cortisol's effects.
20. What is adrenal insufficiency, and how does it differ from Addison's disease?
Adrenal insufficiency is a broader term referring to inadequate production of adrenal hormones. While Addison's disease specifically refers to primary adrenal insufficiency (problem in the adrenal glands themselves), secondary adrenal insufficiency can occur due to problems in the pituitary or hypothalamus.
21. What are the main hormones produced by the adrenal cortex?
The adrenal cortex produces three main types of hormones: mineralocorticoids (primarily aldosterone), glucocorticoids (primarily cortisol), and androgens (such as DHEA and androstenedione).
22. How does the adrenal cortex contribute to maintaining electrolyte balance?
The adrenal cortex produces aldosterone, which regulates sodium and potassium balance in the body. Aldosterone increases sodium reabsorption and potassium excretion in the kidneys, helping maintain proper electrolyte levels and blood pressure.
23. Why are adrenal androgens considered "weak" compared to testicular androgens?
Adrenal androgens, like DHEA and androstenedione, are considered weak because they have less potent androgenic effects than testosterone, which is primarily produced in the testes. However, adrenal androgens can be converted to testosterone in peripheral tissues.
24. What role does the adrenal cortex play in glucose metabolism?
The adrenal cortex produces cortisol, which plays a crucial role in glucose metabolism. Cortisol increases blood glucose levels by promoting gluconeogenesis in the liver, breaking down protein for energy, and reducing glucose uptake in peripheral tissues.
25. How do adrenal cortex hormones affect the immune system?
Glucocorticoids like cortisol have immunosuppressive effects. They reduce inflammation by inhibiting the production of inflammatory mediators and suppressing the activity of immune cells. This is why synthetic glucocorticoids are used to treat various inflammatory and autoimmune conditions.
26. What is the relationship between the adrenal cortex and the hypothalamic-pituitary axis?
The hypothalamic-pituitary-adrenal (HPA) axis regulates adrenal cortex function. The hypothalamus releases corticotropin-releasing hormone (CRH), which stimulates the pituitary to release adrenocorticotropic hormone (ACTH). ACTH then stimulates the adrenal cortex to produce cortisol.
27. How does negative feedback control cortisol production?
When cortisol levels in the blood rise, they inhibit the release of CRH from the hypothalamus and ACTH from the pituitary. This negative feedback loop helps maintain appropriate cortisol levels in the body.
28. How does aldosterone regulate blood pressure?
Aldosterone increases blood pressure by promoting sodium retention and potassium excretion in the kidneys. This leads to increased water retention, which increases blood volume and, consequently, blood pressure.
29. Why is cortisol often called the "stress hormone"?
Cortisol is called the "stress hormone" because its production increases in response to physical or emotional stress. It helps the body cope with stress by mobilizing energy resources, suppressing non-essential functions, and modulating the immune system.
30. How does the adrenal cortex contribute to the body's "fight or flight" response?
While the adrenal medulla is primarily responsible for the immediate "fight or flight" response, the adrenal cortex supports this by increasing cortisol production. Cortisol helps maintain this response by increasing blood glucose levels and enhancing the effects of adrenaline.
31. What is the role of cholesterol in adrenal cortex hormone production?
Cholesterol is the precursor for all steroid hormones produced in the adrenal cortex. The adrenal glands can synthesize cholesterol, take it up from the bloodstream, or use stored cholesterol to produce hormones as needed.
32. What is the role of the adrenal cortex in fetal development?
During fetal development, the adrenal cortex is relatively large and produces androgens that are important for proper development. After birth, the fetal adrenal cortex regresses, and the adult cortex takes over hormone production.
33. How does aging affect the function of the adrenal cortex?
With aging, there's a gradual decline in the production of adrenal hormones, particularly DHEA and its sulfate (DHEA-S). This decline may contribute to some age-related changes, although the full implications are not yet fully understood.
34. What is the significance of the blood-adrenal barrier?
The blood-adrenal barrier, formed by endothelial cells in adrenal capillaries, regulates the passage of molecules between blood and adrenal tissue. It helps control the delivery of hormones and their precursors to and from the adrenal cortex.
35. What is adrenal incidentaloma and how does it relate to adrenal cortex function?
An adrenal incidentaloma is a mass found incidentally on the adrenal gland during imaging for unrelated reasons. While often benign and non-functional, some can produce excess hormones, affecting normal adrenal cortex function.
36. What is the relationship between the adrenal cortex and the renin-angiotensin-aldosterone system (RAAS)?
The RAAS is a hormone system that regulates blood pressure and fluid balance. Angiotensin II, produced in this system, stimulates the adrenal cortex to release aldosterone, which in turn increases sodium and water retention, helping to maintain blood pressure.
37. How do adrenal cortex hormones influence protein metabolism?
Cortisol, produced by the adrenal cortex, promotes protein catabolism (breakdown) in most body tissues except the liver. This provides amino acids for gluconeogenesis, helping to maintain blood glucose levels during stress or fasting.
38. What is the role of 11β-hydroxysteroid dehydrogenase in regulating cortisol activity?
11β-hydroxysteroid dehydrogenase is an enzyme that converts active cortisol to inactive cortisone (type 2) or vice versa (type 1). This helps regulate cortisol activity in different tissues, protecting some organs (like the kidney) from excessive cortisol exposure.
39. How do adrenal cortex hormones influence salt appetite?
Aldosterone, produced by the adrenal cortex, can increase salt appetite. This is part of the body's mechanism to maintain sodium balance and blood pressure, especially when sodium levels are low.
40. How does the adrenal cortex contribute to maintaining acid-base balance?
Aldosterone, produced by the adrenal cortex, plays a role in acid-base balance by promoting potassium excretion and hydrogen ion secretion in the kidneys. This helps maintain proper pH levels in the body.
41. What is the role of steroidogenic acute regulatory protein (StAR) in adrenal cortex function?
StAR is crucial for steroid hormone production in the adrenal cortex. It facilitates the transport of cholesterol from the outer to the inner mitochondrial membrane, which is the rate-limiting step in steroidogenesis.
42. How do adrenal cortex hormones affect cardiovascular function?
Adrenal cortex hormones have various effects on the cardiovascular system. Aldosterone increases blood volume and pressure, while cortisol increases cardiac output and blood pressure by enhancing the sensitivity of blood vessels to catecholamines.
43. How do adrenal cortex hormones influence wound healing and tissue repair?
Cortisol plays a complex role in wound healing. In normal amounts, it supports the inflammatory phase of healing. However, excessive cortisol can impair wound healing by suppressing inflammation and collagen synthesis.
44. What is the significance of 21-hydroxylase in adrenal cortex function?
21-hydroxylase is a crucial enzyme in the synthesis of both mineralocorticoids and glucocorticoids. Deficiency of this enzyme is the most common cause of congenital adrenal hyperplasia, leading to imbalances in adrenal hormone production.
45. How does the adrenal cortex respond to hemorrhagic shock?
In hemorrhagic shock, the adrenal cortex increases cortisol production to help maintain blood pressure, enhance the effects of catecholamines on blood vessels, and mobilize energy resources to cope with the stress of blood loss.
46. What is the role of the adrenal cortex in maintaining normal blood glucose levels during fasting?
During fasting, cortisol from the adrenal cortex helps maintain blood glucose levels by promoting gluconeogenesis in the liver, breaking down protein for energy, and reducing glucose uptake by peripheral tissues.
47. How do adrenal cortex hormones influence mood and cognitive function?
Cortisol affects mood and cognitive function through its actions on the brain. Normal cortisol rhythms are important for cognitive performance and mood regulation. However, both excessive and deficient cortisol levels can negatively impact mood and cognition.
48. What is the relationship between the adrenal cortex and the thyroid gland?
There's a complex interplay between adrenal and thyroid function. Cortisol can inhibit the conversion of T4 to active T3 thyroid hormone. Conversely, thyroid hormones can affect the metabolism of cortisol. This interaction is important in maintaining overall metabolic balance.
49. How does the adrenal cortex contribute to the body's response to infection?
During infection, the adrenal cortex increases cortisol production. Cortisol helps regulate the immune response, reducing inflammation while also maintaining blood pressure and glucose levels to support the body's fight against infection.
50. What is the role of the adrenal cortex in maintaining normal blood pressure during postural changes?
The adrenal cortex, through its production of aldosterone, helps maintain blood pressure during postural changes. Aldosterone promotes sodium and water retention, which helps maintain blood volume and pressure when standing up.
51. How do adrenal cortex hormones affect sleep-wake cycles?
Cortisol levels follow a circadian rhythm, with highest levels in the early morning, helping to wake us up. Disruptions in this rhythm can affect sleep patterns. Conversely, sleep disturbances can also disrupt normal cortisol rhythms.
52. What is the significance of 3β-hydroxysteroid dehydrogenase in adrenal steroidogenesis?
3β-hydroxysteroid dehydrogenase is a crucial enzyme in the synthesis of all classes of steroid hormones in the adrenal cortex. Deficiency of this enzyme can lead to various forms of congenital adrenal hyperplasia, affecting multiple hormone pathways.
53. How does the adrenal cortex respond to severe illness or trauma?
In severe illness or trauma, the adrenal cortex dramatically increases cortisol production. This helps maintain blood pressure, mobilize energy resources, and modulate the immune response to cope with the physiological stress of illness or injury.
54. What is the role of the adrenal cortex in maintaining normal electrolyte levels during prolonged exercise?
During prolonged exercise, the adrenal cortex increases aldosterone production to help maintain electrolyte balance. Aldosterone promotes sodium retention and potassium excretion, which is crucial for maintaining proper hydration and electrolyte levels during extended physical activity.
55. How do adrenal cortex hormones influence appetite and food intake?
Cortisol can influence appetite and food intake in several ways. It can increase appetite, particularly for high-calorie foods. It also interacts with other hormones like insulin and leptin, which regulate hunger and satiety. Chronic high cortisol levels can lead to increased abdominal fat deposition.

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