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

NORCET 6 Prelims -2024

Applied Physiology

Easy

Appeared in: NORCET 6 Prelims -2024

Explanation

The zona fasciculata is the middle and largest layer of the adrenal cortex, making up about 75% of it.
Its primary function is the synthesis and secretion of glucocorticoids, with cortisol being the most important one in humans.
Cortisol plays a critical role in the body's stress response, glucose metabolism, immune function, and inflammation regulation.
The secretion of cortisol from the zona fasciculata is controlled by Adrenocorticotropic hormone (ACTH) from the pituitary gland.

Option A: The adrenal medulla is the inner part of the gland, not a layer of the cortex. It produces catecholamines (epinephrine and norepinephrine), not glucocorticoids.
Option B: The zona glomerulosa is the outermost layer of the adrenal cortex and is responsible for secreting mineralocorticoids, primarily aldosterone, which regulates salt and water balance.
Option C: The zona reticularis is the innermost layer of the adrenal cortex. Its primary role is to secrete androgens (sex hormones), not glucocorticoids.

Visual 1: Diagram - A cross-section of the adrenal gland. The diagram should clearly label the outer capsule, the three layers of the cortex (zona glomerulosa, zona fasciculata, zona reticularis), and the inner adrenal medulla. Each layer should be annotated with the primary hormone it secretes.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Physiology of the Adrenal Gland as background academic context rather than a clinical decision trigger.
Understanding which layer secretes which hormone is crucial for diagnosing and managing adrenal disorders. For example, a tumor in the zona fasciculata can lead to overproduction of cortisol, causing Cushing's syndrome.
Conversely, damage to the adrenal cortex, affecting the zona fasciculata, can lead to a deficiency of cortisol, resulting in Addison's disease. Nurses must recognize the signs of both conditions, such as weight changes, blood pressure instability, and electrolyte imbalances.
What if? - If a patient's lab results showed high cortisol but low ACTH, it would suggest a problem within the adrenal gland itself (e.g., a tumor in the zona fasciculata) rather than a pituitary issue. This distinction guides further diagnostic steps and treatment.

How to Approach the Question

First, identify the keywords in the question: 'adrenal gland', 'layers', and 'glucocorticoids'. This tells you the question is about the specific function of a specific part of an organ.
This is a factual recall question based on anatomy and physiology. Access your knowledge about the endocrine system.
Recall the structure of the adrenal gland: an outer cortex and an inner medulla.
Remember the three layers of the cortex. A useful mnemonic is 'GFR' for the layers from outside to inside: Glomerulosa, Fasciculata, Reticularis.
Associate the layers with their hormonal products using the mnemonic 'Salt, Sugar, Sex'.
Match the hormone type in the question (glucocorticoids = 'Sugar') with its corresponding layer (Fasciculata). This leads to the correct answer.

Concept Tested & Keywords

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