Adrenal glands

Definition

Adrenal glands are small, triangular-shaped glands located on top of each kidney, playing a crucial role in producing hormones that help regulate metabolism, immune response, blood pressure, and stress. These glands consist of two main parts: the outer adrenal cortex, which produces steroid hormones, and the inner adrenal medulla, which produces catecholamines such as adrenaline and noradrenaline. Their function is vital for maintaining homeostasis and responding to physiological stressors.

5 Must Know Facts For Your Next Test

1. Adrenal glands produce over 50 different hormones that impact various bodily functions such as metabolism, immune function, and cardiovascular health.
2. The adrenal cortex has three layers: the zona glomerulosa (producing mineralocorticoids), zona fasciculata (producing glucocorticoids), and zona reticularis (producing androgens).
3. The adrenal medulla releases hormones like epinephrine and norepinephrine during stress, triggering the 'fight or flight' response which prepares the body for rapid action.
4. Disorders of the adrenal glands can lead to conditions such as Cushing's syndrome (overproduction of cortisol) or Addison's disease (underproduction of hormones).
5. The adrenal glands are essential in regulating blood pressure through hormone secretion that affects sodium and water retention in the kidneys.

Review Questions

• How do adrenal glands contribute to the body's response to stress?
  • Adrenal glands play a critical role in the body's stress response by releasing hormones like cortisol from the adrenal cortex and epinephrine from the adrenal medulla. Cortisol helps manage energy usage during stress while modulating immune responses, whereas epinephrine increases heart rate and blood flow to essential muscles. This hormonal release prepares the body for immediate action, enhancing survival during stressful situations.
• Discuss the roles of the different layers of the adrenal cortex in hormone production.
  • The adrenal cortex consists of three distinct layers: the zona glomerulosa produces mineralocorticoids like aldosterone, which regulates sodium and potassium levels; the zona fasciculata produces glucocorticoids like cortisol, important for metabolism and stress response; and the zona reticularis produces androgens, which are precursors to sex hormones. Each layer's hormones have specific roles that contribute to overall homeostasis and physiological balance.
• Evaluate how dysfunction in adrenal gland hormone production can impact overall health.
  • Dysfunction in adrenal gland hormone production can lead to significant health issues. For example, overproduction of cortisol can result in Cushing's syndrome, leading to symptoms like obesity, hypertension, and diabetes. Conversely, underproduction of hormones can cause Addison's disease, characterized by fatigue, weight loss, and low blood pressure. These disorders highlight how critical adrenal hormones are for maintaining normal physiological functions and overall well-being.

Related terms

Cortisol:

A steroid hormone produced by the adrenal cortex that plays a key role in metabolism, immune response regulation, and stress management.

Epinephrine: Also known as adrenaline, it is a hormone produced by the adrenal medulla that increases heart rate, dilates air passages, and aids in the body's fight-or-flight response.

Hormones:

Chemical messengers produced by glands in the endocrine system that regulate various physiological processes in the body.