Pituitary Function

Abstract

This chapter discusses the basic functions of hypothalamus and pituitary gland. The hypothalamic-pituitary system is a preeminent example of the integration of neural and endocrine control. It consists of three major systems: a neuroendocrine system connected to an endocrine system by a portal circulation; a neurosecretory pathway; and a direct neural regulation of endocrine secretion. The neuroendocrine system involves clusters of peptide and monoamine-secreting cells in the anterior and midportion of the ventral hypothalamus. Their products reach the median eminence by axonal transport. The hypothalamus and pituitary control vital functions such as growth, reproduction, lactation, basal metabolism, stress response, parameters of immune function, and the state of hydration. Understanding of the complicated functional relationship of the hypothalamus to the pituitary requires an appreciation of the anatomical relationships. This chapter begins with a discussion on hypothalamus–pituitary system, including anatomical considerations and regulation of pituitary functions. The chapter then discusses basic concepts related to anterior lobe and intermediate lobe. Proopiomelanocortin-derived peptides, glycoprotein hormones, somatomammotropic hormones, and neurohypophysis are also discussed. The chapter concludes with a discussion on the assessment of pituitary function.