Flashcards in Embryology of the Heart Deck (17):
When does the development of the heart take place?
- between weeks 3 and 7 after fertilization
The 1st fold of the heart tube is called the _______, and the 2nd fold is called the _______.
- 1st fold: C-bend
- 2nd fold: S-bend
Arterial blood outflow occurs at the ______ of the heart tube, while venous return inflow occurs at the _______.
- arterial outflow occurs at top
- venous inflow occurs at bottom
What are the three fetal shunts present in the fetal heart?
- ductus venosus (bypasses the liver; blood enters directly into the IVC)
- foramen ovale (hole in atrial septum)
- ductus arteriosus (bypasses the lungs)
T or F: in fetal circulation, the pressure of the right side of the heart is usually greater than that of the left side.
- the two pressures are relatively equal
What occurs when the spiral septum fails to spiral during development?
- transposition of the great vessels
What occurs when the spiral septum spirals off-center during development?
- tetralogy of Fallot
What are the five embryologic structures of the heart (going from the top of the heart tube to the bottom)?
- truncus arteriosus, bulbus cordis, primitive ventricle, primitive atria, and sinus venosus
What does the truncus arteriosus become?
- the ascending aorta and the pulmonary trunk
What does the bulbus cordis become?
- the SMOOTH part of the ventricles
What does the primitive ventricle become? The primitive atria?
- they become the TRABECULATED part of the ventricles and atria, respectively
What does the sinus venosus become?
- the left horn becomes the coronary sinus
What do the endocardial cushions of the outflow tract develop into?
- the aortic and pulmonary valves
What do the fused endocardial cushions of the atrio-ventricle canal develop into?
- the AV valves
Which cells are responsible for the spiraling of the truncus arteriosus?
- neural crest cells
How many embryonic aortic arches form the bifurication of the truncus arteriosus? Separately, which arch forms the aorta? The pulmonary trunk?
- 2 arches form the bifurication
- arch #4 forms the aorta
- arch #6 forms the pulmonary trunk