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 A
Explanation
Asymmetrical chest movement is a sign of respiratory distress in the newborn, as it indicates unequal lung expansion or airway obstruction. A respiratory rate of 50 breaths/minute (choice B) is normal for a newborn, as is acrocyanosis (choice C), which is a bluish discoloration of the hands and feet due to immature peripheral circulation. Short periods of apnea (less than 15 seconds) (choice D) are also common and benign in newborns unless they are associated with bradycardia or cyanosis.
Choice B is not correct because a respiratory rate of 50 breaths/minute is within the normal range for a newborn.
Choice C is not correct because acrocyanosis is a normal finding in newborns and does not indicate respiratory distress.
Choice D is not correct because short periods of apnea (less than 15 seconds) are normal in newborns and do not indicate respiratory distress.
Correct Answer is C
Explanation
Fever. This is because fever is a sign of infection, which is a common and potentially serious postpartum complication. Infection can affect various parts of the body, such as the uterus (endometritis), the bladder (cystitis), the breast (mastitis), the wound (wound infection), or the blood (sepsis). Infection can cause symptoms such as fever, chills, pain, foul-smelling discharge, redness, swelling, or warmth at the site of infection.
Choice A is not correct because the change in lochia from red to white is not a sign of postpartum complication. Lochia is the vaginal discharge that occurs after childbirth. It changes color and amount over time, from red to pink to brown to yellow to white. This is a normal process of healing and does not indicate a problem unless the lochia is foul-smelling, heavy, or contains large clots³.
Choice B is not correct because fatigue and irritability are not signs of postpartum complications. Fatigue and irritability are common feelings after childbirth due to hormonal changes, sleep deprivation, physical recovery, and emotional adjustment. They do not necessarily indicate a problem unless they are severe or persistent and interfere with daily functioning or bonding with the baby.
Choice D is not correct because contractions are not signs of postpartum complication. Contractions are normal after childbirth and help the uterus shrink back to its pre-pregnancy size. They are usually mild and subside within a few days. They may be more intense during breastfeeding due to the release of oxytocin, which stimulates uterine contractions.
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