Embryology of Heart and Lungs Flashcards
What kind of tissues will the trophoblast form?
Extra embryonic tissue (e.g. placenta)
What cell type will give rise to the amniotic membrane/cavity?
Epiblast, dorsal aspect of the disc
What forms the primitive yolk sac?
Hypoblast, Ventral part of the disc
What week does gastrulation occur?
3
What important things is the cardiac crescent ABOVE? (i.e more cranial)
Oropharyngeal membrane
Developing forebrain
What kind of mesoderm gives rise to all layers of heart progenitors?
Splanchnic
What do hemangioblasts form when exposed to vascular endothelial growth factors? What follows?
Blood cells and blood islands. Blood islands unite to form paired endothelial lined endocardial heart tubes.
How are endocardial primordium cells formed?
Splanchnic mesoderm cells that differentiate into epithelial cells
What secretes cardiac jelly? What is it?
ECM between endothelial cell of heart tube and cardiac myocytes. Secreted by myocardial cells.
What are the venous drainage points and outflow tracts of developing heart when its a tube?
Venous drainage = caudal pole Outflow tract (aortic arch) = cranial pole
How is the developing heart suspended in the pericardial cavity? What is its fate?
Dorsal mesocardium, which ultimately breaks down and gives rise to the transverse pericardial cavity.
What are the cranial and caudal attachments of the developing heart tube?
Cranial = pharyngeal arches Caudal = Transverse septum
What is the direct of blood flow in the primitive heart?
Horns of sinus venosus -> Atria (LA) -> Ventricle (LV) -> Bulbis cordis (RA, RV mostly) -> truncus arteriosus (Ao, PA)
How is the asymmetry of the heart formed?
Bending to the RIGHT as part of dextral looping
Which primitive part of the heart experiences the most differential growth?
Bulbis cordis
What looping does the cephalic (e.g. bulbis cordis) portion experience?
Ventral
Caudal
Right
What looping does the caudal portion experience?
Dorsal
Cranial
Left
What happens to the umbilical veins between weeks 4 and 8?
The left if left
The right regresses
What do the common cardinal veins become between weeks 4 and 8?
Brachiocephalic veins
SVC
What is the remnants of the left sinus horn?
Oblique vein of LA
and coronary sinus
What is the remnant of the right sinus horn?
Incorporated into RA as SMOOTH walled portion (sinus venarum) of RA
What is the crista terminalis?
Dividing line between the trabeculated wall (primitive atrium) and smooth wall (from right sinus horn)
What is the ductus venosus?
Shunt to the liver in fetal circulation
What is the foramen ovale?
Hole in fetal circulation that shunts blood from the RA to LA.
