NEONATAL PHYSIOLOGY AND THE STRESSED NEONATE

摘要

Neonates are not miniature adults. Their physiology is unpredictably different from adults. The neonatal period is the physiologic transition period from the aquatic, self-contained fetal life with its full dependence on maternal nutrition, waste handling and environmental homeostasis to independent extrauterine life where birth and breaking the umbilical cord literally means the neonate must adapt its physiology to provide all the necessities of independent life. The term "neonate" is derived from the Latin natus (to be born) and refers to a newborn during the first weeks of life during the physiologic transition. Although strictly speaking it should encompass the entire period until the transition is complete for all organ systems, by convenienceit is usually defined as the first 3 to 4 weeks of life in most domestic species.