Embryology Flashcards
name the four major stages of heart development
- primitive heart tube
- heart looping
- atrial and ventricular septation
- outflow tract septation
what does the lateral plate of the splanchnic mesoderm form in the 3rd week?
the circulatory system (as well as other mesoderm)
what do the angiogenic cell islands do in the third week?
they collect in the lateral plates splanchnic mesoderm and move towards the midline where the coalesce to form two primitive heart tubes
when does the primordial heart begin to function?
at the beginning of week 4
why does the cardiovascular system need to develop first?
the rapidly growing embryo cannot get enough nutrition via diffusion
where do blood vessels first appear?
in the wall of the yolk sac, allantois, connecting stalk and chorion
where do paired endothelial strands (angioblastic cords) appear in week three?
in the cariogenic mesoderm
what do angioblastic tubes canalise to form?
heart tubes
from what is the pericardium derived from?
from the intra-embryonic coelom
what are the parietal and fibrous pericardium formed from?
the somatic mesoderm
what is the visceral layer of the pericardium formed from?
the splanchnic mesoderm
during cephalic folding what structure becomes ventral?
the pericardial cavity
during cephalic folding what structure becomes dorsal?
the cardiac tube
name the 5 parts of the primitive cardiac tube from cranial end to caudal end
> truncus arteriosus > bulbus cordis > ventricle > atrium > sinus venosus
name the three veins that supply the sinus venosus horns
> common cardinal
umbilical
vitelline
where does the vitelline vein get its blood from?
the yolk sac
where does the common cardinal vein get its blood from?
the body of the embryo
where do the aortic arches arise?
from the aortic sac
where do the aortic arches terminate?
in the dorsal aorta
how is the bulboventricular loop formed?
the bulbus cordis and the ventricle grow faster than the other regions forming a U-shaped bulboventricular loop by day 24
what is dextrocardia?
there is situs invertus where the heart loops to the right side so it is facing the right
what does the endocardial cushion formation separate?
the right atrioventricular opening from the left atrioventricular opening
what does the septum formation separate?
he right atrium from the left atrium and the right ventricle form the left ventricle
which septum first grows down from the endocardial tissue?
the septum primum