Question 1

Three days after birth,an infant becomes cyanotic during a prolonged crying spell.The cyanosis is due to venous blood entering the systemic circulation through the ______________.

Accepted Answer

The cyanosis is due to venous blood entering the systemic circulation through the interatrial septum, which suggests a condition like a patent foramen ovale or atrial septal defect, allowing deoxygenated blood to mix with oxygenated blood.

Question 2

The ligamentum teres is the postnatal remains of the ______________.

Accepted Answer

The ligamentum teres is the remnant of the umbilical vein, which in fetal life carries oxygenated blood from the placenta to the fetus.

Question 3

Which of the maturation processes in the fetus is not affected by fetal cortisol?

Accepted Answer

Fetal cortisol does not affect the shift of the main hematopoietic site to bone marrow.

Question 4

Respiratory distress syndrome in premature infants is due to ______________.

Accepted Answer

Respiratory distress syndrome (RDS) in premature infants is primarily due to insufficient production of pulmonary surfactant, not any of the options listed. Surfactant reduces surface tension in the lungs, allowing them to expand more easily with each breath.

Question 5

Insufficient production of ________________ is the most common cause of reduced survival in infants born 8 weeks prematurely.

Accepted Answer

Insufficient production of pulmonary surfactant is the most common cause of reduced survival in infants born 8 weeks prematurely. Pulmonary surfactant is a substance that prevents the collapse of alveoli in the lungs and helps with breathing. Premature infants may not have enough surfactant, causing respiratory distress syndrome (RDS), which can be life-threatening. Treatment for RDS includes administering exogenous surfactant and providing respiratory support.

Question 6

Meconium is formed in the fetal __________.

Accepted Answer

Meconium is the earliest stool of a mammalian infant, composed of materials ingested during the time the infant spends in the uterus, primarily formed in the ileum.

Question 7

Parturition most commonly occurs _______ weeks after fertilization.

Accepted Answer

Parturition, or childbirth, typically occurs about 38 weeks after fertilization, which corresponds to approximately 40 weeks of gestation from the last menstrual period.

Question 8

The most highly oxygenated blood in the fetus is found in the ______________.

Accepted Answer

The umbilical vein carries highly oxygenated blood from the placenta to the fetus, making it the correct answer. The dorsal aorta carries oxygenated blood away from the heart, but it is not the most highly oxygenated blood. The umbilical arteries carry deoxygenated blood from the fetus to the placenta. The pulmonary arteries carry deoxygenated blood from the heart to the lungs, and the pulmonary vein carries oxygenated blood from the lungs to the heart, but neither of these vessels are involved in fetal circulation.

Quiz 18: Fetal Period and Birth