Adrenal cortex

Definition

The adrenal cortex is the outer region of the adrenal glands, which are located atop each kidney. It plays a critical role in the body's stress response by producing vital hormones such as cortisol, aldosterone, and androgens. These hormones help regulate metabolism, immune response, blood pressure, and other essential functions during periods of stress.

5 Must Know Facts For Your Next Test

1. The adrenal cortex has three distinct zones: the zona glomerulosa (producing aldosterone), zona fasciculata (producing cortisol), and zona reticularis (producing androgens).
2. Cortisol, released from the adrenal cortex during stress, mobilizes energy by increasing glucose availability and suppressing non-essential functions like digestion and reproduction.
3. Chronic stress can lead to dysregulation of the adrenal cortex, resulting in conditions like Cushing's syndrome due to excess cortisol production.
4. Aldosterone helps maintain electrolyte balance by promoting sodium retention and potassium excretion in the kidneys, crucial for regulating blood pressure.
5. The adrenal cortex's activity is regulated by adrenocorticotropic hormone (ACTH) from the pituitary gland, which is influenced by feedback from cortisol levels.

Review Questions

• How does the adrenal cortex contribute to the body's physiological stress response?
  • The adrenal cortex contributes to the physiological stress response primarily through the secretion of cortisol. This hormone increases glucose availability for energy, enhances metabolic functions, and suppresses non-essential bodily processes. Additionally, aldosterone from the adrenal cortex helps maintain blood pressure during stress by regulating fluid and electrolyte balance.
• Discuss the implications of chronic stress on the functioning of the adrenal cortex and overall health.
  • Chronic stress can lead to prolonged activation of the adrenal cortex, resulting in excessive production of cortisol. This condition can cause various health issues such as Cushing's syndrome, characterized by weight gain, high blood pressure, and weakened immune function. Additionally, persistent high cortisol levels can disrupt other hormonal balances and lead to mental health problems like anxiety and depression.
• Evaluate how the interplay between the HPA axis and the adrenal cortex regulates hormonal responses to stress and its potential impact on behavior.
  • The HPA axis orchestrates a complex feedback loop involving the hypothalamus, pituitary gland, and adrenal cortex to regulate hormonal responses to stress. When a stressful situation arises, the hypothalamus releases corticotropin-releasing hormone (CRH), prompting the pituitary gland to secrete ACTH, which stimulates cortisol release from the adrenal cortex. This cascade not only helps prepare the body for a fight-or-flight response but can also influence behavior by affecting mood, cognition, and motivation. Dysregulation within this system can lead to behavioral changes and mental health disorders.

Related terms

Cortisol: A steroid hormone produced by the adrenal cortex that helps regulate metabolism, immune response, and stress response.

Aldosterone: A hormone produced by the adrenal cortex that helps regulate sodium and potassium levels in the blood, influencing blood pressure.

HPA Axis: The hypothalamic-pituitary-adrenal axis is a complex set of interactions between the hypothalamus, pituitary gland, and adrenal glands that regulate the body's response to stress.