2006-11-16 03:10:47 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Biology
It starts WAY before the human being is born. The original cells that become specialized to move fluid within the embryonic cluster, begin to beat at just a few days after conception.
2006-11-16 03:14:04 · answer #1 · answered by Anonymous · 0⤊ 0⤋
The human heart actually starts beating well before birth when the human embryo is still in the womb.
This info from Wikipedia at, http://en.wikipedia.org/wiki/Heart
---
The human embryonic heart begins beating approximately 21 days after conception, or five weeks after the last normal menstrual period (LMP), which is the date normally used to date pregnancy. The human heart begins beating at a rate near the mother’s, about 75-80 beats per minute (bpm). The embryonic heart rate (EHR) then accelerates linearly for the first month of beating, peaking at 165-185 bpm during the early 7th week, (early 9th week after the LMP). This acceleration is approximately 3.3 bpm per day, or about 10 bpm every three days, an increase of 100 bpm in the first month. [1]
After peaking at about 9.2 weeks after the LMP, it decelerates to about 150 bpm (+/-25 bpm) during the 15th week after the LMP. After the 15th week the deceleration slows reaching an average rate of about 145 (+/-25 bpm) bpm at term
---
Why the heart starts has to do with the human genes. There are cells which form to become the heart and another set of genes to activate the heart muscles.
Another interesting fact about the embryo's heart is that a tube forms between the right and left side of the heart to bypass the lungs, which have no use until birth. This tube later closes so the heart can pump blood through the lungs to receive oxygen!
Hope this helps!
2006-11-16 11:19:07 · answer #2 · answered by cfpops 5 · 0⤊ 0⤋
The human embryonic heart begins beating approximately 21 days after conception, or five weeks after the last normal menstrual period (LMP), which is the date normally used to date pregnancy. The human heart begins beating at a rate near the mother’s, about 75-80 beats per minute (bpm). The embryonic heart rate (EHR) then accelerates linearly for the first month of beating, peaking at 165-185 bpm during the early 7th week, (early 9th week after the LMP). This acceleration is approximately 3.3 bpm per day, or about 10 bpm every three days, an increase of 100 bpm in the first month.
After peaking at about 9.2 weeks after the LMP, it decelerates to about 150 bpm (+/-25 bpm) during the 15th week after the LMP. After the 15th week the deceleration slows reaching an average rate of about 145 (+/-25 bpm) bpm at term. The regression formula which describes this acceleration before the embryo reaches 25 mm in crown-rump length or 9.2 LMP weeks is:
Age in days = EHR(0.3)+6
There is no difference in male and female heart rates before birth.
2006-11-17 10:06:34 · answer #3 · answered by SP!DEY ! 2 · 0⤊ 0⤋
The heart starts beating around 21 days after fertilization. WELL before the baby is born.
2006-11-16 14:50:40 · answer #4 · answered by v__dawg 3 · 0⤊ 0⤋
Actually, your question has an error. The heart already starts beating in the embryo stage. How else would the embryo survive( If there was no blood circulation ) ?
2006-11-18 06:28:52 · answer #5 · answered by Enlightened 2 · 1⤊ 0⤋
Yeah it starts after conception.
2006-11-16 11:18:16 · answer #6 · answered by It Co$t To Be Around The Bo$$ 4 · 0⤊ 0⤋
It has started already at that point
2006-11-16 11:19:12 · answer #7 · answered by african lion 3 · 0⤊ 0⤋
r u mad?? it starts beatin well b4 that, its as soon as its conceived!!! duhh
2006-11-16 11:46:30 · answer #8 · answered by monaUK 5 · 0⤊ 0⤋