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The Endowment for Human Development
The Endowment for Human Development
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Slideshow: Favorites

Heart in Slow Motion

#67, Slide 1 of 74

4 weeks, 4 days

From The Biology of Prenatal Development.Buy Now

Note:

This video sequence demonstrates the heart's contraction-relaxation cycle. The portion of the cardiac cycle marked by relaxation of the ventricles is called diastole. The portion of the cardiac cycle marked by contraction of the ventricles is called systole.

Label Key:

1. midbrain
2. hindbrain
3. forebrain
4. 1st pharyngeal arch (mandibular process)
5. right edge of mouth (stomodeum)
6. umbilical cord in the background
7. abdominal wall
8. liver
9. heart chambers (outlined in yellow)
All ages referenced to fertilization, not last menstrual period.
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