What is the function of the adrenal glands?

From the Guidelines

The adrenal glands play a crucial role in producing hormones that regulate various bodily functions, including metabolism, stress response, blood pressure, and immune function, with the most recent evidence suggesting their importance in maintaining homeostasis and responding to stress 1. The adrenal glands are vital endocrine organs that consist of two distinct parts: the outer cortex and inner medulla.

• The adrenal cortex produces steroid hormones, including:
  • Cortisol, which regulates metabolism and helps the body respond to stress
  • Aldosterone, which maintains blood pressure by controlling salt and water balance
  • Small amounts of sex hormones
• The adrenal medulla produces catecholamines, such as epinephrine (adrenaline) and norepinephrine, which trigger the "fight-or-flight" response during stress, increasing heart rate, blood pressure, and blood glucose levels. These hormones work together to help maintain homeostasis, manage stress responses, regulate metabolism, control blood pressure, and support immune function, as highlighted in a study on the management of glucocorticoids during the peri-operative period for patients with adrenal insufficiency 1. Dysfunction of the adrenal glands can lead to conditions like Addison's disease (insufficient hormone production) or Cushing's syndrome (excessive cortisol), which require medical intervention to restore proper hormone balance, with recent guidelines emphasizing the importance of physiological replacement therapy and increased dosing during times of physiological stress 1. Key points to consider include:
• The importance of maintaining adequate cortisol levels, particularly in patients with adrenal insufficiency, to prevent adrenal crisis and ensure proper stress response 1
• The need for careful management of glucocorticoids during the peri-operative period to prevent complications and ensure optimal outcomes 1
• The potential for relative adrenal insufficiency in patients with cirrhosis, which can increase the risk of severe sepsis and mortality, and may require hydrocortisone treatment 1

From the FDA Drug Label

ACTIONS Naturally occurring glucocorticoids (hydrocortisone and cortisone), which also have salt-retaining properties, are used as replacement therapy in adrenocortical deficiency states. The adrenal glands produce glucocorticoids, such as hydrocortisone and cortisone, which have various functions, including:

• Replacement therapy in adrenocortical deficiency states
• Salt-retaining properties
• Metabolic effects
• Modifying the body's immune responses 2

From the Research

Adrenal Gland Functions

The adrenal glands are paired endocrine organs that play a vital role in maintaining homeostasis by regulating:

• Blood pressure
• Metabolism
• Electrolyte balance
• The body's response to stress 3 They comprise the adrenal cortex, which produces steroid hormones, and the adrenal medulla, responsible for catecholamine synthesis.

Zones of the Adrenal Cortex

The adrenal cortex is further divided into three functional zones:

• Zona glomerulosa: produces mineralocorticoids
• Zona fasciculata: produces glucocorticoids
• Zona reticularis: produces androgens 3

Adrenal Medulla Functions

The adrenal medulla secretes:

• Adrenaline
• Noradrenaline
• Dopamine under sympathetic control, aiding in blood pressure and blood flow regulation 3, 4

Response to Stress

The adrenal gland plays a major role in the response to physiological challenges and is able to adapt to these physiological needs 5 Proper adaptation is essential for human health, as dysregulation of the stress system can cause various diseases, including obesity, depression, and post-traumatic stress disorder 5

Hormone Secretion

The adrenal glands secrete hormones essential for:

• Metabolism
• Regulation of blood pressure
• Sodium and glucose homeostasis 6 Hypo- or hypersecretion of these hormones can be life-threatening, making it crucial to understand the physiological functions of adrenal hormones 6