| Popis: |
The pituitary gland is often referred to as the master gland because it orchestrates many of the endocrine processes required for growth and development, regulation of metabolic rate, sexual maturation and reproduction, initiation and maintenance of lactation, response to stress and regulation of water balance. The pituitary gland is divided into two lobes—the anterior pituitary and the posterior pituitary. The anterior pituitary is composed of specialized cells, each responsible for producing and secreting a single hormone in response to hormone signals from both the hypothalamus and peripheral endocrine glands. The posterior pituitary can be considered an extension of the hypothalamus and does not synthesize hormones, rather it releases hormones produced by the hypothalamus in response to appropriate stimuli. Disorders of the anterior and posterior pituitary are characterized by either hormone excess or insufficiency and the clinical laboratory often plays a critical role in the diagnosis of these disorders and monitoring patients’ responses to therapy. This chapter will discuss the physiological effects of the anterior and posterior pituitary hormones, describe the regulatory mechanisms responsible for their release, define clinical signs and symptoms consistent with dysregulated pituitary hormone function and suggest appropriate clinical laboratory tests for the evaluation of suspected pituitary dysfunction. |
