Talk:Historic Animation - Heart 04

From Embryology

Part 1 Summary

Introduction to early development

Heart layers - epicardium, myocardium, endocardium

Week 3 Heart Fields Epicardiomantle Mesenchymal cells Endocardium development from double to single tube Cephalic end connects with dorsal aortas Caudal end connects with vitelline veins

End Week 3 Single thin-walled tube Tube bengins to bend

Part 2 Summary

Scale Bar 1 mm

Sinus venosus - draining fluid and blood cells from 3 pairs of vessels (vitelline veins, umbilical veins, common cardinal veins) common cardinal veins = ducts of Cuvier

Heart tube - bends ventrally to the right

Primitive atria - above sinus venosus

Conus - above primitive atria

Truncus arteriosus - above conus

Aortic arches - above truncus arteriosus

Caudal to cranial sequence sinus venosus - primitive atria - conus - truncus arteriosus - aortic arches

Middle Week 3

Splanchnopleuric mesoderm - differentiated into epimyocardial mantle around the tubes

Two heart tubes - brought together by the folding of the body

Foregut - lies dorsal to the heart tubes

End Week 3

Spontaneous cardiac contractions

Detachment of the heart tube dorsally

Primordia of transverse sinus of the pericardium

Part 3 Summary

Four separate shifts of position

Week 4

  • Shift 1 - Head fold growth rotates heart and cavity 180 degrees
  • Shift 2 - Curvature of the body, cephalic growth

Week 5

  • 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

Part 4 Summary

Week 7 - (outflow) aortic and pulmonary trunks completely separated

Week 8 - external form similar to that at birth

0.5 mm to 5 mm growth

Week 4 - Dorsal view, Sinus venosus migrates towards the right

End of week 4 forth arches appear

sinus venosus single opening into atria

Week 5 - branched pulmonary vein arises

hepatic part of inferior vena cava (IVC) developing within liver

right pulmonary arch declining to disappear

Week 6 - pulmonary branches taken up by left atrium

Week 7 and 8 - superior vena cava (SVC) migrates upwards

End of Week 8 - coronary sinus, draining veins of cardiac wall

Week 11 - 4 secondary pulmonary branches have openings into the left atrium