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Early Development of the Heart - Coggle Diagram
Early Development of the Heart
Prevalence of Heart Malformations
Leading cause of birth defect-associated infant morbidity and mortality.
6,000 deaths annually in the U.S. (1999-2006) due to congenital heart defects.
Formation of the Heart
Endocardial Tubes
Paired tubes form within the visceral layer of lateral plate mesoderm.
Fuse and bulge into the pericardial cavity as the body wall and gut tube fold.
Migration of the Heart:
Forebrain enlargement causes the heart to fold ventrally into the thorax.
Pericardial cavity and septum transversum are pulled with it.
Contraction of the Heart
Mesenchyme around the endocardial tube differentiates into myocardium.
Myocardium begins beating at ~22 days.
Blood flows from inferior to superior through the heart tube.
Inferior parts receive blood; superior parts propel blood through aortic arches and aortae.
Embryonic Chambers
Sinus venosus
Primordial atrium
Ventricle
Bulbus cordis
Aortic sac
Folding of the Heart
Heart enlarges and folds within the pericardial cavity.
Detaches from the dorsal mesocardium.
Creates
Transverse pericardial sinus
Bulboventricular loop
Atria positioned posterior to ventricles.
Forms U-shaped and S-shaped loops.
Building Blocks of the Mature Heart
Five embryonic regions modify to form the four-chambered heart.
Sinus venosus
→ Right atrium, vena cavae, and coronary sinus.
Primordial ventricle
→ Left ventricle.
Bulbus cordis
→ Muscular right ventricle.
Conus cordis
→ Smooth outflow portions of right and left ventricles.
Truncus arteriosus
→ Proximal aorta and pulmonary trunk.
Aortic sac
→ Aorta and pulmonary artery.
Flow of Blood
Blood flows continuously through the developing heart.
Structures involved:
Truncus arteriosus
Conus cordis
Bulbus cordis
Aortic sac
Ventricle
Atrium
Sinus venosus