Deck 10: Fetal Development and the Cardiopulmonary System

Question 1

At what gestational age are as many as 75 percent of the conducting airways developed?

A) 8-10 weeks
B) 10-14 weeks
C) 17-27 weeks
D) 28-30 weeks

Answer 1

B

Question 2

How many alveoli would be expected in a 12-year-old child?

A) 24 million
B) 100 million
C) 50 million
D) > 240 million

Answer 2

D

Question 3

Which of the following would be most likely to develop after delivery of a newborn at 27 weeks gestational age?

A) Tetralogy of Fallot
B) meconium aspiration
C) Coarctation of the aorta
D) PPHN

Answer 3

D

Question 4

At what gestational age after fertilization are all major bronchi present?

A) pseudoglandular
B) canalicular
C) embryonic period
D) terminal saccular

Question 5

Which of the following contribute to the wide variance between maternal and fetal P_O2 and P_CO2?
I. The placenta is an actively metabolizing organ
II. Regional variations occur in placental permeability
III. Maternal and fetal vascular shunts occur

A) I, II, and III
B) I and III only
C) I and II only
D) II and III only

Question 6

At what gestational age does the terminal saccular period begin?

A) 26 weeks
B) 20 weeks
C) 24 weeks
D) 22 weeks

Question 7

In a full-term newborn, how many alveoli are present at birth?

A) 240 million
B) 200 million
C) 24 million
D) 50 million

Question 8

At what gestational age does the placenta begin to develop?

A) Day 7
B) Day 5
C) at implantation of the fertilized egg
D) Day 3

Question 9

Where does fetal lung fluid originate?

A) from the stomach and esophagus
B) from maternal lymph vessels
C) from alveolar cells
D) from aspiration of amniotic fluid

Question 10

What of the following influence the oxygen transfer from maternal to fetal blood?
I. Maternal-fetal PO₂ gradient
II. Higher hemoglobin concentration in fetal blood
III. Lower affinity of HbF for oxygen

A) II and III only
B) I, II, and III
C) I and II only
D) I and III only

Question 11

At what gestational age do primitive respiratory bronchioles appear?

A) 12-16 weeks
B) 25-28 weeks
C) 17-26 weeks
D) 8-12 weeks

Question 12

What is the term for the premature separation of the placenta from the uterine wall?

A) placenta percreta
B) placenta accreta
C) placenta previa
D) abruptio placentae

Question 13

Which vessels transports oxygenated blood and nutrients from the placenta to the fetus?

A) umbilical artery
B) umbilical vein
C) placental artery
D) placental vein

Question 14

After birth, into what structure does the umbilical vein evolve?

A) lateral umbilical ligament
B) ligamentum venosum of the liver
C) ligamentum teres (round ligament) of the liver
D) ligamentum arteriosum

Question 15

How is fetal lung fluid normally removed?
I. Squeezed out during vaginal delivery
II. Absorbed by the pulmonary capillaries
III. Absorbed by the lymphatic system
IV. Removed by vigorous endobronchial suctioning by the delivery room staff

A) I, II, III, and IV
B) I, II, and III only
C) II and III only
D) I and II only

Question 16

Which of the following structures would compose the placental cotyledons?
I. Fetal vessels
II. Chorionic villi
III. Intervillous spaces

A) I and II only
B) I only
C) I, II, and III.
D) I, II, and III

Question 17

What is the term for the procedure in which a sample of the fluid surrounding a fetus is removed via a needle inserted through the uterine wall and the fluid sample is analyzed for abnormalities?

A) chorionic villi sampling
B) thoracentesis
C) amniocentesis
D) sonography

Question 18

What is the normal P_O2 in the umbilical arteries?

A) 20 mm Hg
B) 40 mm Hg
C) 80 mm Hg
D) 55 mm Hg

Question 19

In the fetus, where does the majority of blood flow go after leaving the right atrium?

A) left atrium
B) left ventricle
C) pulmonary artery
D) right ventricle

Question 20

At what gestational age do lung buds first appear?

A) 16th week
B) 26th day
C) 21st week
D) 28th day

Question 21

What response would be expected if a newborn of 28 weeks gestational age received endotracheal suctioning?

A) no change in respiratory rate would occur
B) bradypnea or apnea would occur
C) tachypnea would occur followed by apnea
D) the newborn would take a breath on top of a breath

Question 22

Which of the following factors contribute to stimulate the first breath?
I. Tactile stimulation
II. Stimulation of central chemoreceptors
III. Stimulation of peripheral chemoreceptors
IV. Thermal stimuli

A) I and IV only
B) I, II, III, IV
C) I, II, and III only
D) II and III only

Question 23

What is the most common cause of respiratory failure in preterm infants?

A) BPD
B) RDS
C) pneumonia
D) meconium aspiration

Question 24

Which of the following nerves, when stimulated, causes a decrease in the respiratory and heart rates of the newborn?

A) VII cranial nerve
B) IX cranial nerve
C) phrenic
D) V cranial nerve (trigeminal)

Question 25

During the first 72 hours in the life of a healthy newborn, what changes would be expected in arterial blood gases?
I. pH would increase
II. PaCO₂ would decrease
III. HCO₃- would increase
IV. PaO₂ would increase

A) II and IV only
B) I, II, III, and IV
C) I and IV only
D) I, II, and IV only

Question 26

What of the following factors cause a reduction in the pulmonary vascular resistance following the first breath?
I. Increased alveolar pressure of oxygen
II. Removal of lung fluid which reduces pressure on pulmonary vessels
III. Increase in lung volume, which widens the caliber of extralveolar vessels

A) I, II, and III
B) II and III only
C) I only
D) I and II only

Question 27

What is the average lung compliance of a neonate?

A) 0.005 mL/cm H20
B) 0.5 L/cm H20
C) 0.050 L/cm H20
D) 0.005 L/cm H20

Question 28

What factor causes closure of the foramen ovale?

A) increased blood pressure in the right atrium
B) increased PO2 in the arterial blood
C) increased blood pressure in the left atrium
D) increased PCO2 in the arterial blood

Question 29

If a registered respiratory therapist successfully completes the NBRC's neonatal/pediatric specialty credential, what credential would be awarded?

A) CRT-NPS
B) RRT-NPS
C) NPRCS
D) None-no such credential exists

Question 30

What intrapleural pressure must be generated to initiate the first breath?

A) -4 cm H20
B) -40 cm H20
C) -400 cm H20
D) 40 cm H20

Question 31

What would you conclude regarding a fetus' lung maturity if the S:A ratio equaled 60?

A) uncertain lung maturity
B) unable to make a conclusion since the S:A ratio does not assess lung maturity
C) fetal lung maturity
D) immature fetal lungs

Question 32

What is the average value for airway resistance in a newborn?

A) 3 cm H20/L/sec
B) 0.50 L/sec/cm H20
C) 0.005 /L/ sec/cm H20
D) 30 cm H20/L/sec

Question 33

What does the presence of phosphatidyglycerol (PG) in the amniotic fluid indicate?

A) uncertain fetal lung maturity
B) immature fetal lungs
C) high risk of development of respiratory distress
D) low risk of development of respiratory distress

Question 34

Constriction of the ductus arteriosus occurs in response to

A) the newborn's increased PO2
B) the increase in blood pressure in the left atrium
C) the increase in blood pressure in the pulmonary artery
D) the newborn's decreased pH

Question 35

What is the normal respiratory rate of an average newborn?

A) 35-50/min
B) 46-69/min
C) 25-35/min
D) 60-80/min