embryology of cardiovascular system Flashcards
what is the pericardial cavity formed from?
intraembryonic coelom
in week 3, what is the cardiogenic field?
when blood vessels first appear in yolk sac
what do blood vessels in lateral plate splanchnic mesoderm form?
2 primitive heart (endocardial) tubes
how is the primordial cardiovascular system formed?
heart tubes fuse and join blood vessels in other areas
what does truncus arteriousus form?
ascending aorta and pulmonary trunk
aortic sac -> aortic arches
what does bulbus cordis form?
smooth parts
aortic vestibule of the left ventricle
conus arteriosus of the right ventricle
what does the primitive ventricle form?
trabecular(rough) walls of left and right ventricles
what does the primitive atrium form?
left and right atria
what does the sinous venous form?
coronary sinus
smooth walls of the right atrium
what is the fold of the primitive heart tube called?
bulboventricular loop
describe the formation of bulboventricular loop
bulbus cordis and ventricle enlarge and loop to the right
atrium pushed frontwards, down and right
ventricle pushed backwards, up and left
what is dextrocardia?
abnormal cardiac looping of heart tube to the left
what does the endocardial cushion growth do?
divides atrioventricular canal into left and right.
what is the role of foramen ovale before and after birth?
before birth
- allows passage of blood
- prevents blood moving in opposite direction
after birth
- closes due to increased pressure
describe the formation of primitive atrium into left and right atria
septum primum forms and extends to endocardial cushion which makes a ostium(hole/gap)
before ostium (hole) primum closes, another hole (ostium secundum) forms in the septum primum
a second septum (secundum) forms with a hole called foremen ovale -> blood shunt
what happens to septum primum and septum secundum after birth?
they fuse together
what is fossa ovalis
remnant of foramen ovale
what happens to ductus arteriosus?
la of lpa and a
ligamentum arteriosum between left pulmonary artery and aorta
what happens to ductus venosus?
lv of l
becomes ligamentum venosum of liver
what is a patent (open) foramen ovale?
common congenital atrial septal defect
- hole in the heart
describe partition of primitve ventricle
muscular ventricular septum forms
forms an opening between ventricles
-> interventricular foramen
aorticopulmonary septum spirally divides bulbus cordis and truncus arteriosus
-> aorta and pulmonary trunk
bottom of spiral aorticopulmonary septum fuses with muscular ventricular septum and endocardial cushion
-> membranous interventricular septum
interventricualr foramen closes
what is the most common congenital heart defect?
ventricular septal defect
during week 5, how many bilateral aortic arches are formed from aortic sac of truncus arteriosus?
6 pairs
what happens to 1st, 2nd and 5th aortic arches?
disappears
what happens to the 3rd aortic arches?
forms carotid arteries
what happens to the 4th right aortic arch?
forms right subclavian artery
what happens to 4th left aortic arch?
forms aortic arch
what happens to 6th right aortic arch?
forms right pulmonary artery
what happens to 6th left aortic arch?
forms left pulmonary artery and ductus arteriosus
