Embryology Flashcards
Bulbus Cordis
Smooth (inflow tracks) of Right and Left Ventricles
What structures are derived from the Endocardial Cushion
Atrial Septum, Membraneous intraventricular septum, AV and Semilunar valves
Coronary Sinus
Left horn of Sinus Venosus
Inferior Vena Cava
Sub-cardinal, Supra cardinal and Posterior cardinal veins
What structures are derived from the Primitive Atrium
Trabecular part of the right and left atria
Primitive Pulmonary Vein
The smooth part of the left atrium
Primitive Ventricle forms
Trabecular part of the Right and Left Ventricles
Right common cardinal and Right Anterior cardinal vein
Superior Vena Cava
Right Horn of Sinus Venosus
The smooth part of Right Atrium (Sinus Venarum)
Truncus Arteriosus
Ascending Aorta and the Pulmonary Trunck
The heart is the first functional organ in vertebrae embryos
beats spontaneously by 4 weeks
primary heart tube loops to
Establish right-left polarity
Right- Left polarity begins in
the 4th week of gestation
Defect in Right- Left Dynein
Dextrocardia see in Kartagener syndrome
Kartagener Syndrome
primary ciliary Dyskinesia
can have Dextrocardia
due to Defect in Dynein
Atrial Septation
1) Septum Primum
2) Foramen secundum
3) Septum secundum
1) Grows towards the endocardial cushion and narrows the foramen primum
2) Forms in the Septum Primum (Foramen Primum disappears )
3a) the Spetum Secumdum develops while the Foramen Secundum maintains R-> L Shunt
3b) Septum Secundum expands to cover most of the foramen secundum
3c) Remaining opening forms the foramen ovale
3d) the remaining portion of septum primum forms the valve of the foramen ovale
Foramen ovale
Formed by the remaining opening of the foramen secundum
The remaining portion of the Septum Primum
Forms the valve of the foramen ovale
The septum secundum and the Septum Primum fuse to form
Atrial Septum
Foramen ovale closes soon after birth because
There is an increase in pressure in the Left Atrium and decrease pressure in the Right Atrium
Patent foramen ovale
Due to failure of fusion of the Septum secundum and Septum primum
Risk of a patent foramen ovale
Migration of a thromboembolic into the systemic arterial circulation
Ventricles formation
1) muscular Interventricular septum forms
2) The opening present is called the intraventricular foramen
3) Aorticoplumonary septum rotates and fuses with the muscular ventricular septum forming the membranous interventricular septum closing the intraventricular foramen
4) Growth of the Endocardial cushions separates atria from ventricles and contributes to both atrial septation and the membranous portion of the interventricular septum.
Most common Congenital Cardiac anomaly
Ventricular Septal Defect
Most common location of Ventricular Septal Defect
Membranous Septum
Aorticopulmonary septum rotates and fuses with
the membranous ventricular septum
Growth of the Endocardial cushion separates the
atria from ventricles and contributes to both atrial septation and the membranous portion on the interventricular septum.
Outflow Tract formation
Neural crest and endocardial cells migrations
- > truncal ridges and bulbar ridges that spiral and fuses to form the aorticopulmonary septum
- > ascending aorta and pulmonary trunk
Name 3 Conotruncal abnormalities associated with failure of the Neural crest cells to migrate
1) Transposition of the Great vessels
2) Tetralogy of Fallot
3) Persistent Truncus Arteriosus
Valve development
Aortic and pulmonary valves are derived from
The endocardial cushions of the outflow tract
Valve Development
Mitral and Tricuspid valves are derived from
Fused endocardial cushions of the AV canal
Valvular anomalies can be
1) Stenotic
2) Regurgitant
3) Atretic (tricuspid atresia)
4) Displaced (Ebstein anomaly)
