Anatomy and Physiology of Pregnancy Flashcards

What is the name of the specialized circulatory structure in the fetus that allows blood to bypass the non-functioning lungs?

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.

During pregnancy, which change to the maternal respiratory system helps compensate for increased oxygen demand?

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.

The fundal height in centimeters roughly corresponds to which measurement after 20 weeks?

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.

Which presentation occurs when the baby's buttocks or feet are positioned toward the cervix rather than the head?

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.

What anatomical change causes many pregnant women to experience shortness of breath in the third trimester?

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.

The plug of mucus that seals the cervical os during pregnancy is called:

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.

Which fetal organ is responsible for gas exchange, nutrient transfer, and hormone production during pregnancy?

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.