The master gland controls the thyroid gland, adrenal gland, ovaries and testicles. While it may be in charge of these glands, it gets it orders from its neighbor, the hypothalamus. 

Basically, glands and hormones are a long communication chain in the body. The hypothalamus sends signals in the form of hormones to the pituitary gland, telling it just how much hormones are needed to send to the other glands. Then, the pituitary secretes hormones that signal to the glands how much hormones they need to secrete. 

The pituitary gland also produces hormones for organs in the body, as well. It creates: 

• Oxytocin for the uterus and mammary glands to stimulate contractions that aid in birth and milk production
• Vasopressin, an antidiuretic hormone, for the kidneys
• Beta-melanocyte-stimulating hormone that darkens the skin
• Endorphins for the brain and immune system to help inhibit pain sensations and regulate the immune system
• Growth hormones for muscles and bones 
• Enkephalins that help inhibit pain sensations in the brain
• Prolactin, which stimulates milk production in the mammary glands 

Most hormones are released every one to three hours and run in conjunction with the body's circadian rhythm. This means that hormone production is at its peak during the day hours and level off as night falls.  Other hormones rely on certain factors, such as the menstrual cycle, to determine production levels.