NURSING 101 Chapter 33: Alterations of Cardiovascular Function in Children

. Most cardiovascular developments occur between which weeks of gestation? a. Fourth and seventh weeks c. Twelfth and fourteenth weeks b. Eighth and tenth weeks d. Fifteenth and seventeenth weeks ANS: A Cardiogenesis begins at approximately 3 weeksÕ gestation; however, most cardiovascular development occurs between 4 and 7 weeksÕ gestation. PTS: 1 REF: Page 1194 2. The function of the foramen ovale in a fetus allows what to occur? a. Right-to-left blood shunting c. Blood flow from the umbilical cord b. Left-to-right blood shunting d. Blood flow to the lungs ANS: A The nonfused septum secundum and ostium secundum result in the formation of a flapped orifice known as the foramen ovale, which allows the right-to-left shunting necessary for fetal circulation. The foramen ovale is not involved in the blood flow described by the other options. PTS: 1 REF: Pages 3. At birth, which statement is true? a. Systemic resistance and pulmonary resistance fall. b. Gas exchange shifts from the placenta to the lung. c. Systemic resistance falls and pulmonary resistance rises. d. Systemic resistance and pulmonary resistance rise. ANS: B From the available options, the only change that takes place in the circulation at birth is the shift of gas exchange from the placenta to the lungs.