Four separate shifts of cardiac position
Week 4 (Gestational Age - week 6)
- Shift 1 - Head fold growth rotates heart and cavity 180 degrees
- Shift 2 - Curvature of the body, cephalic growth
Week 5 (Gestational Age - week 7)
- Shift 3 and 4 - Growth of the liver
Week 4 - First aortic arches declining, Third arches well developed
- Myogenic contractions sufficient to circulate blood
- Atrium migrates to higher location
Week 5 - Ventricles do not contract simultaneously
Week 6 - Separation of outflow has begun
Next: Part 4
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