fetal circulation and embryology Flashcards
at 21 to 23 days in embryo the heart consist of
the heart tubes are forced to midline during a folding process that fuses them into a single tube
the sinus venosus is formed by
the union off 3 veins (common, vitelline, and umbilical)
the sinus venosus becomes the…
SVC , IVC, pulmonary veins, coronary sinus and oblique vein of the LV and posterior portions and of the right/left atria
the primitive atria divides into
the right and left atria
the atrioventricular sulcus divides into
primitive atria and ventricle
proximal bulbus cordis gives rise to
trabecular expansion that forms the apex of the RV
mid portion of the bulbus cordis forms the
right and left outflow tracts
distal bulbus cordis or truncus arteriosus forms the
aorta and MPA
1st aortic arch
pair regresses
2nd aortic arch
leads to mandibular and maxillary arteries
3rd aortic arch
leads to common and internal carotid arteries.
4th aortic arch
leads to adult aorta and forms the left subclavian and braciocephalic trunk
6th aortic arch
derive the main left and right pulmonary arteries
the endocardial cushion develops into
mitral and tricuspid valves
when is the fetal heart development complete
at 7 weeks or 49 days
when does the heart start to beat
3 weeks or 21 days
name the 3 shunts in fetal circulation
foramne ovale
ductus arteriosus
ductus venosus
process of fetal circulation
- placenta
- umbilical vein
- small blood into liver
- blood shunted through ductus venosus
- IVC
- RA
- some blood through RA to RV to MPA
- most blood shunted through formane ovale
- blood bypasses the lungs through ductus arterious
- through aorta
the remnant of the ductus arterious becomes the
ligamentum arteriosum
the remnant of the ductus venosum becomes
ligament venosum
the umbilical veins becomes which ligament
the ligamentum teres
