TY - CHAP M1 - Book, Section TI - Chapter 80. Fundamental Concepts of Child Development A1 - Rudolph, Colin D. A1 - Rudolph, Abraham M. A1 - Lister, George E. A1 - First, Lewis R. A1 - Gershon, Anne A. PY - 2011 T2 - Rudolph's Pediatrics, 22e AB - No single construct has been more central in the development of the biologic sciences than homeostasis. Although the term homeostasis was coined in the 20th century, its conceptual origin can be traced to the notion of a stable, relatively unchanging internal environment, which was first described by Claude Bernard in the 19th century. Bernard recognized the fragility of life, surrounded as it is by a constantly threatening, aversive, and often pathogenic environment, and he argued that viability in the face of external challenge depends on an organism’s capacity for protecting its internal milieu. In this context, homeostasis is a dynamic, self-regulating process that ensures constancy and permanence in the internal physiologic state through complex, multilevel feedback systems that respond to a deviation in one direction with a countering adjustment in the opposite direction. Thus, the fundamental goal of a homeostatic system is to maintain an inerrant “set point” that assures stable and continuous biologic functioning. The regulation of body temperature, cortisol suppression of adrenocorticotropic hormone (ACTH) secretion, and glycogenolysis during periods of hypoglycemia are all examples of feedback loops that protect the continuity and equilibrium of an organism’s interior. SN - PB - The McGraw-Hill Companies CY - New York, NY Y2 - 2024/04/19 UR - accesspediatrics.mhmedical.com/content.aspx?aid=6737737 ER -