PMC Prenatal Anatomy & Physiology 2 — Questions and Answers
Question 1: Which hormone is primarily responsible for relaxing pelvic ligaments during pregnancy?
- Relaxin (Correct answer)
- Progesterone
- Estrogen
- Oxytocin
Correct answer: Relaxin
Relaxin is secreted by the corpus luteum and placenta, softening ligaments and preparing the pelvis for delivery.
Question 2: The uterus rises out of the pelvis and becomes an abdominal organ at approximately which week of gestation?
- 8 weeks
- 12 weeks (Correct answer)
- 20 weeks
- 28 weeks
Correct answer: 12 weeks
By 12 weeks the uterus is large enough to rise above the pelvic brim and become palpable as an abdominal organ.
Question 3: What structural change in the diaphragm occurs as the uterus enlarges in the third trimester?
- It descends approximately 4 cm
- It is displaced superiorly by about 4 cm (Correct answer)
- It thickens to support increased pressure
- It rotates laterally to accommodate the fetus
Correct answer: It is displaced superiorly by about 4 cm
The enlarging uterus pushes abdominal contents upward, elevating the diaphragm by approximately 4 cm.
Question 4: During pregnancy, maternal blood volume increases by approximately what percentage?
- 15–20%
- 30–50% (Correct answer)
- 60–75%
- 80–100%
Correct answer: 30–50%
Total blood volume increases 30–50% during pregnancy to meet the perfusion demands of the placenta and fetus.
Question 5: Which plexus of veins is at risk for varicosities due to increased pelvic pressure during pregnancy?
- Brachial plexus
- Pudendal plexus (Correct answer)
- Celiac plexus
- Lumbar plexus
Correct answer: Pudendal plexus
The pudendal venous plexus drains the perineum and vulva and is compressed by the gravid uterus, leading to vulvar varicosities.
Question 6: Diastasis recti refers to the separation of which abdominal structure?
- Internal and external oblique muscles
- Linea alba between the rectus abdominis muscles (Correct answer)
- Transversus abdominis fascia
- Inguinal ligament from the pubic symphysis
Correct answer: Linea alba between the rectus abdominis muscles
Diastasis recti is the midline separation of the two rectus abdominis muscles along the linea alba due to uterine stretching.
Question 7: The round ligaments of the uterus connect the uterus to which anatomical structure?
- Sacrum via the uterosacral ligaments
- Labia majora through the inguinal canal (Correct answer)
- Ovaries via the mesovarium
- Bladder base through the pubovesical fascia
Correct answer: Labia majora through the inguinal canal
The round ligaments travel through the inguinal canal and insert into the labia majora, anchoring the uterus anteriorly.
PMC Prenatal Anatomy & Physiology 2
Which hormone is primarily responsible for relaxing pelvic ligaments during pregnancy?