During which week does the fetal heart begin pumping its own blood?
A. 3rd week
B. 4t week
C. 5th week
D. 6th week
Correct Answer: B. 4t week
Explanation
The fetal heart begins pumping its own blood at the end of the 3rd week of gestation (around day 22–23).
Explanation
- Early development (3rd week):
The heart develops from mesoderm. During the third week, paired heart tubes form and then fuse to create a primitive heart tube. - Onset of pumping (day 22–23):
As soon as the primitive heart tube is formed, it starts rhythmic contractions. These contractions are effective enough to pump blood within the embryo, even before the heart is fully formed. - 4th week:
During the fourth week, the heart undergoes looping and chamber formation, making blood circulation more organized. However, pumping has already started by the end of the 3rd week.
Key exam point
- Correct answer: End of 3rd week (≈22nd day)
- Heartbeat detectable by ultrasound later (around 5–6 weeks), but pumping starts much earlier.
👉 In summary: The fetal heart is the first functional organ, and it begins pumping its own blood by the end of the 3rd week of pregnancy.
Other Options Details
Question: During which week does the fetal heart begin pumping its own blood?
Correct answer: A. 3rd week
Below is an explanation of all options:
A. 3rd week ✅ (Correct)
- The heart develops from mesoderm as a primitive heart tube.
- By day 22–23 (end of the 3rd week), the heart tube begins spontaneous rhythmic contractions.
- At this stage, the fetal heart starts pumping blood on its own, even before it is fully formed.
- This is the earliest functioning organ in the embryo.
B. 4th week
- During the 4th week, the heart undergoes looping and chamber formation.
- Blood circulation becomes more organized.
- Although the heart is more developed, pumping has already started earlier, so this is not the correct answer.
C. 5th week
- Further septation of chambers (atria and ventricles) occurs.
- Valves begin to develop.
- The heart continues pumping, but initiation of pumping does not begin in this week.
D. 6th week
- The heart becomes more structurally mature.
- Heartbeat can often be detected by ultrasound.
- This week represents maturation, not the beginning of blood pumping.
Summary
- 🫀 Fetal heart begins pumping its own blood in the 3rd week of development
- Hence, the correct answer is A. 3rd week
I hope that you liked this article.
Thanks!! 🙏 😊
Writer: Vandita Singh, Lucknow (GS India Nursing Group