Introduction Platelets are the sentinels of the circulatory system; they recognize and rapidly respond to a disruption in vascular integrity, thereby preventing significant blood loss. This is achieved through the formation of a primary hemostatic plug, which requires platelets to…
Introduction The presence of a complex hemostatic system is fundamental to all multicellular organisms with a blood circulatory system. Blood must remain in a fluid form to flow, and for survival, organisms must be able to stop that flow at…
Introduction Megakaryocytes (MKs), among the rarest and most unusual hematopoietic cells in the human bone marrow, comprise 0.02% to 0.1% of the total nucleated marrow cells. , Over the past decades, the study of these cells lagged behind that of…
Acknowledgments Parts of this chapter were adapted from sections of Chapter 134 by authors James A. Stockman III and Pedro A. DeAlarcon in the first edition of this book. We thank Erin Adair for assistance with illustrations. Erythrocyte Kinetics Sites…
Introduction From their initial emergence in the yolk sac at the beginning stages of embryogenesis to their vast proliferation in the bone marrow at the end of term gestation, the differentiation of the pluripotent hematopoietic stem cell into a mature,…
Introduction The hematopoietic system is made up of all of the blood cells, including red blood cells, platelets, myeloid cells such as granulocytes, monocyte-macrophages, and dendritic cells (DC), and lymphoid cells such as T, B, and natural killer (NK) cells.…
Introduction The majority of the existing information on the regulation of acid-base homeostasis in mammals and humans was obtained from studies in adult subjects. Revolution in micromethodology and advances in developmental physiology and molecular biology provided additional insights and improved…
Introduction The human body is composed of fluids and solids (proteins, fat, and minerals). Total body water (TBW) is inversely related to body fat content because fat has very low water content. Body water also contains an array of dissolved…
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…