Movie Theater
The Heart in Action |
 From The Biology of Prenatal Development. |
|
Script: The heart typically beats about 113 times per minute. Note how the heart changes color as blood enters and leaves its chambers with each beat. The heart will beat approximately 54 million times before birth |
|
All ages referenced to fertilization, not last menstrual period.
|
|
The Heart in Action
( 4 weeks, 4 days) |
Hand Plates and Cartilage
( 5 weeks, 6 days) |
Hand Movement
( 6 weeks, 6 days) |
Fingers and Toes
( 7 weeks, 4 days) |
Spontaneous Movement
( 8 weeks) |
Reflexive Movement
( 8 weeks) |
|
|
