Puberty is the stage of development during which secondary sexual characteristics appear and there is a transition from the sexually immature to the sexually mature stage. Adolescence is widely used as a generally synonymous term for puberty, but it is…
Introduction Endocrine neoplasms comprise a variety of benign and malignant tumors that arise from the endocrine glands or other neuroendocrine tissues, such as the paraganglia. Most childhood endocrine tumors, typified by papillary thyroid carcinoma, are sporadic and not attributable to…
History, embryology, and anatomy The adrenal cortex produces three principal categories of steroid hormones that regulate a wide variety of physiologic processes from fetal to adult life. Mineralocorticoids, principally aldosterone, regulate renal retention of sodium and thus profoundly influence electrolyte…
Introduction Thyroid disease can present with overt symptoms, insidiously, or with isolated thyromegaly. Thyroid disease in children can encompass isolated biochemical abnormalities that have little or no physiological consequence, or with overt clinical symptoms. Clinically, hypothyroidism occurs more commonly than…
Introduction Maintenance of the tonicity of extracellular fluids within a very narrow range is crucial for proper cell function. Extracellular osmolality regulates cell shape, as well as intracellular concentrations of ions and other osmolytes. Furthermore, proper extracellular ionic concentrations are…
Introduction Human growth is an astonishing process. Its beginnings are intertwined with the enormously intricate mechanisms that transform a single cell into a complex embryo. Once formed, the human fetus and then child continue to grow over the course of…
Introduction Diabetes is a heterogeneous disorder with many different possible causes, both genetic and acquired. Risk for the most common causes, type 1 and type 2 diabetes, depends on many different gene loci with intermediate or low effects and are…
Calcium (Ca), phosphorus (as phosphate [HPO 4 2− ]), and magnesium (Mg) are essential nutrients that are indispensable for the structural integrity of the body and for the function of each of its cells. The genetic and physiological mechanisms that…
Introduction The thyroid axis is probably the best example of the physiological interactions between the mother, the fetus, and their environment. The discovery of the crucial role of maternal iodine intake for the normal development of the fetus also led…
Introduction One of the most important metabolic events to mark the transition from fetal to neonatal life is the adaptation from an environment that has a readily available and continuous source of glucose—transplacental passage of maternal blood—to an environment in…