Which gland is the 'master gland'?

• A. Exocrine
• B. Pituitary
• C. Adrenal
• D. Thyroid

Answer: (B)

The pituitary gland acts as the master gland because it sends hormonal signals that regulate other endocrine glands and many bodily processes. It sits at the brain base and receives releasing and inhibiting inputs from the hypothalamus, then releases hormones that direct the activity of other organs. The anterior portion secretes hormones like TSH to stimulate the thyroid, ACTH to drive the adrenal cortex, LH and FSH to the gonads, prolactin to the mammary glands, and growth hormone for growth and metabolism. The posterior portion releases vasopressin (ADH) and oxytocin, which are actually produced in the hypothalamus but stored and released by the pituitary. This coordinating role across multiple glands is why the pituitary is described as the master gland, whereas the other options are specific glands that respond to pituitary signals.