Cardiovascular- Embryology Flashcards
What does the truncus arteriosis give rise to?
ascending aorta and pulmonary trunk
What does the bulbus cordis give rise to?
smooth parts (outflow tract) of right and left ventricles
What does the primitive atrium give rise to?
trabeculated part of the left and right atria
What does the primitive ventricle give rise to?
trebaculated part of the left and right ventricles
What does the primitive pulmonary vein give rise to?
smooth part of the left atrium
What does the left horn of the sinus venosus give rise to?
coronary sinus
What does the right horn of the sinus venosus give rise to?
smooth part of the right atrium (sinus venarium)
What do the right common cardinal vein and right anterioe cardinal vein give rise to?
SVC
When can a heart beat be heard?
4 weeks
What is cardiac looping?
the primary heart tube loops to establish left-right polarity beginning at week 4 of gestation
NOTE that a defect in left-right dynein can lead to dextrocardia as seen in Kartagener syndrome
What are the first 2 steps in atrial development?
1) the septum primun grows toward the endocardial cushions, narrowing the foramen primum
2) the foramen secundum forms in the septa primum, as the foramen primum dissappears
What are the next steps in atrial development?
3) the septum secundum develops downward and covers most of the foramen secundum, with the residual foramen being the foramen ovale
4) The remaining portion of the septum primum forms the valve of the foramen ovale
What happens to the foramen ovale at birth?
It usually closes due to increasing L.A. pressure
What causes a patent foramen ovale?
failure of the septum primum and septum secundum to fuse after birth
What are the steps of ventricular development?
1) the muscular ventricular septum forms leaving a connection between the two developing ventricles called the interventricular foramen
2) Aorticopulmonary septum rotates and fuses with the muscular ventricular spetum to form the membranous interventricular septum, closing the interventricular foramen
3) growth of endocardial cushions seperate the atria from the ventricles