Childbirth Educator Anatomy and Physiology of Pregnancy 2 — Questions and Answers
Question 1: What is the name of the specialized circulatory structure in the fetus that allows blood to bypass the non-functioning lungs?
- Ductus arteriosus
- Foramen ovale
- Ductus venosus
- All of the above (Correct answer)
Correct answer: All of the above
All three — the ductus arteriosus, foramen ovale, and ductus venosus — are fetal circulatory shunts that divert blood away from the lungs and liver until birth.
Question 2: During pregnancy, which change to the maternal respiratory system helps compensate for increased oxygen demand?
- Increased respiratory rate only
- Decreased tidal volume
- Increased tidal volume with mild hyperventilation (Correct answer)
- Decreased diaphragmatic excursion
Correct answer: Increased tidal volume with mild hyperventilation
Progesterone stimulates an increase in tidal volume (amount of air per breath), leading to a mild respiratory alkalosis that favors oxygen transfer to the fetus.
Question 3: The fundal height in centimeters roughly corresponds to which measurement after 20 weeks?
- Weeks of gestation minus 2
- Weeks of gestation (Correct answer)
- Weeks of gestation plus 4
- Biparietal diameter in millimeters
Correct answer: Weeks of gestation
After 20 weeks, fundal height in centimeters typically corresponds to the number of weeks of gestation (±2 cm), making it a quick clinical estimation tool.
Question 4: Which presentation occurs when the baby's buttocks or feet are positioned toward the cervix rather than the head?
- Transverse lie
- Cephalic presentation
- Breech presentation (Correct answer)
- Oblique lie
Correct answer: Breech presentation
Breech presentation means the fetal buttocks or feet are the presenting part, which can complicate vaginal delivery and often prompts consideration of cesarean birth.
Question 5: What anatomical change causes many pregnant women to experience shortness of breath in the third trimester?
- Decreased lung capacity from uterine pressure on the diaphragm (Correct answer)
- Increased blood viscosity
- Reduced hemoglobin levels
- Compression of the trachea
Correct answer: Decreased lung capacity from uterine pressure on the diaphragm
As the uterus enlarges in the third trimester, it pushes the diaphragm upward, reducing lung expansion capacity and causing dyspnea.
Question 6: The plug of mucus that seals the cervical os during pregnancy is called:
- Bloody show
- Lochia
- Mucous plug (Correct answer)
- Cervical cap
Correct answer: Mucous plug
The mucous plug forms early in pregnancy to seal the cervix and protect the uterus from ascending infection, and is typically expelled as labor approaches.
Question 7: Which fetal organ is responsible for gas exchange, nutrient transfer, and hormone production during pregnancy?
- Umbilical cord
- Amniotic sac
- Placenta (Correct answer)
- Chorion
Correct answer: Placenta
The placenta performs all major exchange functions — oxygen and CO2 gas exchange, nutrient and waste transfer, and synthesis of hormones like hCG, progesterone, and estrogen.
Childbirth Educator Anatomy and Physiology of Pregnancy 2
What is the name of the specialized circulatory structure in the fetus that allows blood to bypass the non-functioning lungs?