Why do you suppose the brain goes to the trouble of synthesizing releasing hormones, rather than simply directing the production of the pituitary hormones immediately?
Hormones secreted by the posterior lobe of the pituitary gland are actually synthesized by the neurons in the hypothalamus and stored in their axon ends in the posterior lobe for release, when required. The pituitary was called the Master endocrine gland, because of the number of hormones it produces and the control it exercises over other endocrine glands. However, it itself is under control of the releasing hormones secreted by the hypothalamus of the brain. Thus there is a chain of disorders, the hypothalamus directs the pituitary output, which controls the secretion of hormones by other endocrine glands.
