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,…
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…
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…
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…
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…
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…
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…
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…
Introduction Throughout history, humans have sought to understand the differences between biological sexes and the mechanisms responsible for these biological differences. Normal gonadal differentiation and sex development depend on the…
Introduction What makes one an effective user of the clinical laboratory? Such a user: • Identifies at least one sympathetic ally in the clinical laboratory to whom one can reach…
