Acknowledgments The authors are supported by the following funding: PG: NICHD, Pediatric Scientist Development Program (PSDP) and K12-HD000850. FL: R01DK118140, R01DK107653. JC: R01DK110622, R01DK111861, U34DK117128. Introduction Glomerular endowment is highly variable in humans. Although each kidney contains approximately 1 million…
Introduction The functions of the fetal kidney in utero remain little understood. Prior to delivery, the placenta regulates fetal homeostasis of salt and water, and fetal acid-base balance in the context of the acid load generated by intrauterine metabolism and…
Acknowledgments We acknowledge with great sadness the passing of Dr. Michael Linshaw, the renowned pediatric nephrologist who contributed the “Concentration and Dilution of Urine” chapter to this textbook for several editions. He was a beloved teacher and mentor who enjoyed…
Acknowledgments This work was partly supported by NIH grant U54 HD090259. Introduction Rapid and complex changes in physiology occur when the fetus transitions from an intrauterine to an extrauterine environment. From dependency on the maternal circulation via the placenta for…
Introduction Amino acids are the building blocks for proteins and are critical for growth. In addition, they are involved in many metabolic processes within mammalian cells. Thus, regulating their circulating concentrations in the bloodstream is very important for many metabolic…
Acknowledgments We acknowledge the coauthors of this chapter in the previous edition: Drs. Abhijeet Pal, Juhi Kumar, Craig B. Woda, Robert P. Woroniecki, and Susan E. Mulroney. Introduction Calcium and phosphate serve many complex and vital functions. They are key…
Introduction Potassium is the most abundant intracellular cation. Maintenance of a high intracellular potassium concentration (100 to 140 mEq/L) is essential for many basic cellular processes, including cell growth and division, DNA and protein synthesis, conservation of cell volume and…
Introduction The kidney is responsible for maintaining a constant composition and volume of the extracellular fluid. This steady state is achieved by the remarkable capacity of the kidney to maintain sodium balance between what is absorbed in the intestine and…
Introduction The production of urine begins with the formation of an ultrafiltrate of plasma by the glomerulus. The function of the tubule is to modify this ultrafiltrate to allow an efficient excretion of waste products and the retention of those…
Introduction Newborn mammals, including humans, exhibit lower renal blood flow than their adult counterparts. The low fetal and neonatal renal blood flows are maintained by a high renal vascular resistance and establish the newborn’s unique renal functional state, which is…