When a newborn takes its first breath, what physical changes occur in the heart to increase oxygenation of the body?
The ductus arteriosus expands to allow more blood to enter the lungs
The foramen ovale closes, preventing blood exchange from right to left in the heart
The umbilical vein that carried oxygenated blood in utero becomes the ascending aorta entering the right atrium
The ductus venosus shunts oxygenated aortic blood to the lungs.
The Correct Answer is B
The foramen ovale closes, preventing blood exchange from right to left in the heart. This is because the foramen ovale is a fetal shunt that allows blood to bypass the lungs and flow from the right atrium to the left atrium. After birth, when the baby starts to breathe air, the lungs expand and the pulmonary resistance decreases. This causes an increase in blood flow and pressure in the left atrium, which pushes the foramen ovale closed. This prevents blood from mixing between the right and left sides of the heart and allows oxygenated blood to circulate to the body¹².
Choice A is not correct because the ductus arteriosus does not expand to allow more blood to enter the lungs. The ductus arteriosus is another fetal shunt that
connects the pulmonary artery to the aorta. It allows blood to bypass the lungs and flow from the right ventricle to the aorta. After birth, when the baby starts to breathe air, the oxygen concentration in the blood increases and causes the ductus arteriosus to constrict and close. This increases blood flow to the lungs and decreases blood flow to the aorta.
Choice C is not correct because the umbilical vein that carried oxygenated blood in utero does not become the ascending aorta entering the right atrium. The umbilical vein is a fetal vessel that carries oxygenated blood from the placenta to the fetus. It connects to either the portal vein or the ductus venosus, which then drains into the inferior vena cava. After birth, when the umbilical cord is clamped and cut, the umbilical vein collapses and becomes a fibrous cord called ligamentum teres hepatis.
Choice D is not correct because the ductus venosus does not shunt oxygenated aortic blood to the lungs. The ductus venosus is another fetal vessel that connects the umbilical vein to the inferior vena cava. It allows some of the oxygenated blood from the placenta to bypass the liver and enter directly into the systemic circulation. After birth, when the umbilical cord is clamped and cut, the ductus venosus closes and becomes a fibrous cord called ligamentum venosum.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
This can be from the sudden withdrawal of your hormones. It is not a cause for alarm. This is because newborn female babies may have a little bloody vaginal discharge in their diapers due to the withdrawal of maternal hormones after delivery. This usually stops as the hormones return to normal levels. The nurse should reassure the mother that this is a normal and harmless phenomenon and does not require any treatment.
Choice A is wrong because the blood is not related to cleaning her perineal area. The nurse should not blame the mother for being careless.
Choice B is wrong because the baby does not need an appointment for this condition. The nurse should not alarm the mother unnecessarily.
Choice C is wrong because the mother does not need to watch her baby for this condition. The nurse should not leave the mother in doubt or anxiety.
Correct Answer is D
Explanation
Sternal or chest retractions. This is because sternal or chest retractions are a sign of respiratory distress in newborns, which means they are having difficulty breathing. Chest retractions occur when the baby's chest pulls in with each breath, indicating that they are using extra muscles to breathe. This can be caused by various conditions that affect the lungs, such as respiratory distress syndrome (RDS), transient tachypnea of the newborn (TTN), meconium aspiration syndrome (MAS), pneumonia, or congenital heart defects.
Choice A is not correct because mucus draining from the nose is not a symptom of respiratory distress in newborns. It is normal for newborns to have some mucus in their nose and mouth after birth, which can be cleared by suctioning or wiping.
Mucus drainage does not interfere with breathing unless it is excessive or thick.
Choice B is not correct because cyanosis of the hands and feet is not a symptom of respiratory distress in newborns. It is normal for newborns to have bluish discoloration of their hands and feet, called acrocyanosis, for the first few days after birth. This is due to immature circulation and does not indicate a lack of oxygen. Cyanosis of the central parts of the body, such as the face, lips, and tongue, is more concerning and should be reported.
Choice C is not correct because irregular heart rate is not a symptom of respiratory distress in newborns. It is normal for newborns to have some variations in their heart rate, especially during sleep cycles. The normal heart rate range for newborns is 100 to 160 beats per minute. A heart rate that is too fast (tachycardia) or too slow (bradycardia) may indicate a problem with the heart or other organs³.
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