|
Heart
|
Timing
|
Source |
The embryo begins to form a heart.
|
Day 18 after conception |
Rugh, p 17 |
| The heart begins to pump. |
Day 22 after fertilization |
Larsen, p xi |
| The heart begins to beat. |
Day 22 after fertilization |
Moore, p 5; Larsen, p 104 |
| The heart begins to beat |
Day 22 after fertilization |
England, p 104 |
| The heart starts to beat. |
Day 24 after fertilization |
Rugh, p 17 |
| Blood begins to circulate throughout
the embryo. |
Day 24 |
Larsen, p 104 |
| The heart begins to pump. |
4th week of development |
Sadler, p 77 |
| The separation of the heart into a
primordial atrium and ventricle can be seen. |
Day 28 after fertilization |
Larsen, p xi |
|
Coronary vessels appear.
Echocardiography can detect heart movements.
|
Day 32 after fertilization
About day 34 after fertilization
|
Larsen, p xi
Williams, p 30
|
| It is probable that the heartbeat
of the embryo is similar to an adult's heartbeat. |
Week 5 1/2 after conception |
Rugh, p 53 |
| The heart is contracting at a rate
of 40 to 80 beats per minute, as measured with an
electrocardiogram. |
6th-7th weeks after conception |
Rugh, p 53 |
| The fetal heart is functionally complete
and normal. |
7th week after conception |
Rugh, p 53 |
