Cord Blood Umbilical Cord 5 — Questions and Answers
Question 1: After birth, the umbilical vein eventually becomes which adult anatomical structure?
- Ligamentum arteriosum
- Round ligament of the liver (ligamentum teres hepatis) (Correct answer)
- Medial umbilical ligament
- Falciform ligament
Correct answer: Round ligament of the liver (ligamentum teres hepatis)
The umbilical vein obliterates postnatally and becomes the round ligament (ligamentum teres hepatis) of the liver.
Question 2: Which infectious pathogen can be transmitted to the fetus through the umbilical blood vessels and is screened for in cord blood banking units?
- Streptococcus agalactiae
- Cytomegalovirus (CMV)
- Hepatitis B virus
- All of the above (Correct answer)
Correct answer: All of the above
Cord blood banks screen units for multiple pathogens including CMV, hepatitis B, HIV, and bacterial contamination to ensure transplant safety.
Question 3: What happens to umbilical cord stem cells if the collected volume is too small to meet banking thresholds?
- They are used immediately for research
- The unit is typically discarded or donated to a public bank at reduced threshold (Correct answer)
- They are frozen and combined with a future donation
- They are expanded in culture before freezing
Correct answer: The unit is typically discarded or donated to a public bank at reduced threshold
Units that fall below private banking thresholds are often discarded or redirected to public banks that may accept lower-volume units for research or low-weight patients.
Question 4: What is the primary reason cord blood hematopoietic stem cells can be stored and used decades after collection?
- They are preserved in Wharton's jelly at room temperature
- Cryopreservation in liquid nitrogen at −196°C halts cellular metabolism (Correct answer)
- The cells naturally enter a dormant state when cut from the placenta
- Anti-aging proteins in cord blood prevent degradation
Correct answer: Cryopreservation in liquid nitrogen at −196°C halts cellular metabolism
Cryopreservation in liquid nitrogen essentially stops all biological processes, allowing cord blood stem cells to remain viable for 20+ years.
Question 5: Umbilical cord blood banking for a sibling who has a known genetic disorder is called:
- Autologous banking
- Directed allogeneic banking (Correct answer)
- Altruistic donation
- Therapeutic banking
Correct answer: Directed allogeneic banking
Directed allogeneic banking involves storing a newborn's cord blood specifically for use by a related recipient, such as a sibling with a blood disorder.
Question 6: Which of the following best explains why HLA matching is less stringent for cord blood transplants than for bone marrow transplants?
- Cord blood cells lack HLA antigens entirely
- The immunological naivety of cord blood T-cells allows for greater HLA mismatch tolerance (Correct answer)
- Cord blood is always autologous so matching is unnecessary
- Cryopreservation destroys HLA surface markers
Correct answer: The immunological naivety of cord blood T-cells allows for greater HLA mismatch tolerance
The immature T-cells in cord blood are less likely to mount a strong GvHD response, permitting up to 2 HLA mismatches versus bone marrow standards.
Question 7: What is the primary role of the umbilical cord's spiral (helical) structure?
- To increase the length of the cord
- To protect vessels from compression and torsion during fetal movement (Correct answer)
- To allow nutrients to diffuse more efficiently
- To prevent nuchal cord formation
Correct answer: To protect vessels from compression and torsion during fetal movement
The helical coiling of the umbilical cord acts as a natural spring, protecting blood vessels from kinking or compression during fetal activity.
Cord Blood Umbilical Cord 5
After birth, the umbilical vein eventually becomes which adult anatomical structure?