Which of the following layers of the adrenal gland secretes glucocorticoids?

AIIMS Patna NO - 2020

Applied Physiology

Easy

Appeared in: AIIMS Patna NO - 2020

Explanation

The zona fasciculata is the middle and widest layer of the adrenal cortex, making up about 75% of its total volume.
Its primary function is to synthesize and secrete glucocorticoids, with cortisol being the most significant one in humans.
The secretion of cortisol by the zona fasciculata is stimulated by the Adrenocorticotropic hormone (ACTH) from the pituitary gland.
Glucocorticoids like cortisol are vital for regulating metabolism (especially of glucose), managing the body's response to stress, and suppressing the immune system and inflammation.

Option A: The adrenal medulla is the innermost part of the adrenal gland, not a layer of the cortex. It is functionally and embryologically distinct from the cortex.
Option B: The zona glomerulosa is the outermost layer of the adrenal cortex.
Option C: The zona reticularis is the innermost layer of the adrenal cortex, adjacent to the medulla.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Anatomy and Physiology of the Adrenal Gland as background academic context rather than a clinical decision trigger.
Understanding the specific functions of each adrenal layer is fundamental for diagnosing and managing endocrine disorders. For example, a tumor in the zona fasciculata can lead to Cushing's syndrome due to excess cortisol production.
Conversely, destruction of the adrenal cortex, affecting all three layers, leads to Addison's disease, characterized by a deficiency in cortisol, aldosterone, and androgens, which is a life-threatening condition requiring hormone replacement therapy.
What if? If a patient presents with symptoms of virilization (e.g., hirsutism in females), a nurse should consider that the pathology might be in the zona reticularis, which produces androgens, rather than the zona fasciculata.

How to Approach the Question

First, identify the key terms in the question: 'adrenal gland', 'layers', and 'glucocorticoids'. The question asks for the specific layer that produces glucocorticoids.
Recall the basic structure of the adrenal gland, which consists of an outer cortex and an inner medulla.
Remember that the adrenal cortex is further divided into three zones. A common mnemonic for the layers from outside to inside is GFR: Zona Glomerulosa, Zona Fasciculata, and Zona Reticularis.
Associate the primary hormone type with each layer. A useful mnemonic is 'Salt, Sugar, Sex' corresponding to GFR: Glomerulosa -> Mineralocorticoids (Salt), Fasciculata -> Glucocorticoids (Sugar), and Reticularis -> Androgens (Sex).
The question asks for the source of glucocorticoids ('Sugar'), which corresponds to the Zona Fasciculata.
Evaluate the options: Adrenal medulla (catecholamines), Zona glomerulosa (mineralocorticoids), Zona reticularis (androgens), and Zona fasciculata (glucocorticoids). Select the option that matches your conclusion.

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