Which gland is known as the "master gland" of the endocrine system?

The pituitary gland is often referred to as the "master gland" of the endocrine system because it plays a crucial regulatory role in controlling various hormonal functions in the body. It produces and secretes a range of hormones that influence other endocrine glands, such as the adrenal glands, thyroid gland, and gonads. For example, it releases adrenocorticotropic hormone (ACTH) that stimulates the adrenal glands to produce cortisol, and thyroid-stimulating hormone (TSH) that prompts the thyroid gland to secrete thyroid hormones.

The pituitary gland is situated at the base of the brain and acts as a key communication hub, receiving signals from the hypothalamus, which helps to regulate the body's homeostasis and stress responses. This central role in hormonal regulation and its influence over other glands underscore its designation as the "master gland."

The other glands listed, while important for their specific functions, do not have the same level of overarching regulatory influence over the endocrine system as the pituitary gland does. The thyroid gland primarily regulates metabolism, the adrenal gland is involved in stress and metabolic responses, and the pancreas plays critical roles in digestion and blood sugar regulation but does not exert control over other glands.