Which gland is known as the 'master gland'?

The pituitary gland is known as the “master gland.” This small endocrine gland sits at the base of the brain in a bony cavity called the sella turcica and is connected to the hypothalamus by a stalk. Its hormones influence several other glands and help coordinate growth, reproduction, stress responses, metabolism, and water balance.

The nickname is useful but slightly simplified. The pituitary does not independently command the entire endocrine system: the hypothalamus controls much of its activity by sending releasing or inhibiting hormones. The anterior pituitary produces hormones such as growth hormone, ACTH, TSH, FSH, LH, and prolactin. The posterior pituitary stores and releases oxytocin and vasopressin, which are made in the hypothalamus.

The word pituitary comes from an old anatomical belief that the gland produced nasal mucus; that idea was later disproved. Another common mistake is assuming the gland is physically large because of its title. In humans it is roughly kidney-bean-sized, yet its hormonal influence reaches organs throughout the body.