NUR MISC - Newborn Study Guide.

NUR MISC - Newborn Study Guide/NUR MISC - Newborn Study Guide. Caring for the Newborn Study Guide. 1. Define the anatomical structures which function in the circulatory system during fetal existence and close at birth or shortly thereafter. • The foramen ovale, closes shortly after birth. The infant’s first breaths, combined with increased alveolar capillary distention, inflate the lings and reduce pulmonary vascular resistance to the pulmonary blood flow from the pulmonary arteries. Pulmonary artery pressure drops, and pressure in the right atrium declines. Increased pulmonary blood flow from the left side of the heart increases pressure in the left atrium, which cause the closure. During the first few days, crying may reverse the flow and lead to mild cyanosis. In most infants, it is permanently closed within a few months