Why is pituitary gland called the master gland??

The pituitary gland is called the 'master gland' as the hormones it produces control so many different processes in the body. It senses the body's needs and sends signals to different organs and glands throughout the body to regulate their function and maintain an appropriate environment. It secretes a variety of hormones into the bloodstream which acts as messengers to transmit information from the pituitary gland to distant cells, regulating their activity. For example, the pituitary gland produces prolactin, which acts on the breasts to induce milk production. The pituitary gland also secretes hormones that act on the adrenal glands, ovaries, and testes, which in turn produce other hormones. Through secretion of its hormones, the pituitary gland controls metabolism, growth, sexual maturation, reproduction, blood pressure, and many other vital physical functions and processes.