Which of the following is a master gland which influences the endocrine glands?

RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Applied Anatomy

Easy

Appeared in: RUHS, Jaipur, M.Sc Nursing Entrance Exam-2015

Explanation

The pituitary gland is commonly referred to as the "master gland" because it produces and secretes tropic hormones.
These tropic hormones travel through the bloodstream to stimulate and regulate the function of other major endocrine glands, including the thyroid, adrenal glands, and gonads.
For example, Thyroid-Stimulating Hormone (TSH) from the pituitary stimulates the thyroid gland, and Adrenocorticotropic Hormone (ACTH) stimulates the adrenal cortex.
While it is the master gland, the pituitary itself is controlled by releasing and inhibiting hormones from the hypothalamus.

Option A: The thyroid gland is a target of the pituitary gland. It produces hormones that regulate metabolism, but its function is controlled by Thyroid-Stimulating Hormone (TSH) released from the pituitary.
Option B: The parathyroid glands primarily regulate calcium and phosphate levels in the blood. Their function is mainly controlled by the level of calcium in the blood, not by the pituitary gland.
Option C: The adrenal glands, specifically the adrenal cortex, are target glands controlled by the pituitary's Adrenocorticotropic Hormone (ACTH). They are crucial for the stress response but do not control other glands.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Function of the Pituitary Gland as the Master Gland as background academic context rather than a clinical decision trigger.
Understanding the pituitary's role as the master gland is crucial for nurses, as pituitary dysfunction (e.g., a tumor) can cause widespread hormonal imbalances affecting growth, metabolism, blood pressure, and reproduction.
A patient with a pituitary adenoma might present with symptoms related to the specific hormone being overproduced (like Cushing's disease from excess ACTH) or from the tumor's mass effect, such as headaches and vision changes (bitemporal hemianopsia).
What if? If a patient has low levels of thyroid hormone (T4) but also low levels of TSH, the problem is likely not with the thyroid itself but with the pituitary (secondary hypothyroidism) or hypothalamus. This highlights the importance of checking pituitary hormone levels when investigating endocrine disorders.

How to Approach the Question

Identify the key phrase in the question: "master gland".
This is a classic anatomical and physiological term. Access your foundational knowledge of the endocrine system's hierarchy.
Recall that the endocrine system has a command structure. The hypothalamus controls the pituitary, and the pituitary, in turn, controls several other glands.
Evaluate the options: The thyroid, parathyroid, and adrenal glands are all important, but they are 'downstream' glands that are regulated by other hormones.
Conclude that the pituitary gland fits the description of a 'master' controller for many other endocrine glands.

Concept Tested & Keywords

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