With regard to the development of the respiratory system,maternity nurses should be aware that:
A)The respiratory system does not begin developing until after the embryonic stage.
B)The infant's lungs are considered mature when the lecithin/sphingomyelin (L/S) ratio is 1:1,at about 32 weeks.
C)Maternal hypertension can reduce maternal-placental blood flow,accelerating lung maturity.
D)Fetal respiratory movements are not visible on ultrasound scans until at least 16 weeks.

Question

Quizplus · Accepted Answer

A reduction in placental blood flow stresses the fetus,increases blood levels of corticosteroids,and thus accelerates lung maturity. Development of the respiratory system begins during the embryonic phase and continues into childhood. The infant's lungs are mature when the L/S ratio is 2:1,at about 35 weeks. Lung movements have been seen on ultrasound scans at 11 weeks.

With Regard to the Development of the Respiratory System,maternity Nurses