Development of the Heart Lecture Points Flashcards
the heart starts as a …
blood vessel
where do embryonic blood vessels form?
splanchnic layer of later plate mesoderm
where do extraembryonic blood vessels form?
yolk sac mesoderm cells
which area of the embryo (cranial and lateral to prochordal plate) does the heart form?
cardiogenic area
where are angiogenic cell clusters found?
coelomic area
transverse and longitudinal folding is critical to the …
positioning of the heart
which structures allow blood to flow into the heart?
RL sinus venosus
how many atria do adults have?
two
how many ventricles do adults have?
two
explain the process of lateral folding
endocardial heart tubes brought to midline positions where they fuse and separate from guttube (by breakdown of dorsal mesocardium) and suspends freely
what two structures “grow immensely” and drive the positioning of the mature heart?
left ventricle and bulbis cordis
adult left ventricle derived from …?
primitive ventricle and bulbus/conus cordis
adult right ventricle derived from …?
bulbus/conus cordis
aortic arch forms the …
dorsal LR aorta
aortic arch is associated with what …?
pharyngeal arches
why are cardiac defects tolerated so well?
not a major source of gas exchange in the fetal period (the placenta is)
right atrium of the heart derived from?
R horn of the sinus venosus
left atrium of the heart derived from?
portion of primitive pulmonary veins
primitive atria derived from …?
portions of both atria (RL)
path between septum primum and septum secundum is called the …
foramen ovale
closure of the foramen primum results from the fusion of ….
septum primum and endocardial cushion
why is the foramen ovale important?
permits blood flow from RL atria during fetal development
at birth, which side of the lungs has the most pressure?
left
a complete interatrial septum is made from …?
septum primum and septum secundum
if there is R hypertension, how does blood flow?
right to left
right to left shunt of blood possible, cyanosis may result
patent foramen ovale
“physical hole”; mixing of RL blood
secundum atrial septal defect
what two structures are found in the outflow region?
bulbus cordis and truncus arteriosus
which septum is the “spiraling septum”?
aortic pulmonary septum
why are facial and cardiovascular defects typically found together?
they are both neural crest cell derived
the interventricular septum is composed of … ?
muscular and membranous part (fused w/ endocardial cushions)
name the space between the endocardial cushions and the muscular septum that allows open communication up until the 7th week
interventricular foramen
