1BASIC NEUROENDOCRINOLOGY AND THE ANATOMY OF THE HYPOTHALAMUS

The human pituitary gland lies snugly and securely nestled at the base of the brain in a boney pouch known as the sella turcica. This arrangement provides the pituitary with a great deal of protection from physical assaults and, until relatively recently, has also effectively deterred the curious from discovering the secrets of its function. Hovering over the pituitary like a broody hen over her only chick lies a ventromedial area of the brain called the hypothalamus (Fig. 1). The proximity of these two organs accurately reflects a functional relationship between them; however, it is not safe to conclude, on the basis of their small size, that the pituitary and hypothalamus are relatively unimportant. The pituitary gland operates as an endocrine transducer whereby the brain, working through the hypothalamus, controls a number of important body functions. A defect in either pituitary or hypothalamic regulatory mechanisms can seriously impact the well-being of an individual. Neuroendocrinology is the study of how the endocrine and nervous systems interact. The scope of neuroendocrinology is broad, and much of it deals with trying to understand how the brain controls pituitary hormone secretion. The purpose of this chapter is to provide