Heart Development Flashcards
In the adult heart, blood with low oxygen concentration enters the (left/right), while oxygenated blood enters the (left/right) side.
low oxygenated (venous blood) = right oxygenated (arterial) = left
Do lungs function during fetal life?
No
In fetal life, oxygenated blood from _____ to _____
From placenta to RA
In early embryo, what start to differentiate into endothelial cells? What do they form?
Mesenchymal cells – form primitive blood cells (will eventually anastomose to form vascular system)
Where does the formation of primitive blood cells occur in early embryo?
At the wall of the yolk sac outside of the embryo proper
How does heart primordium form?
Differentiation of endothelial tubes withs ome blood cells
Where does heart primoridum originally form? What will occur due to location?
Originally placed above neural plate (above what will be brain). Requires tremendous movement and developmental rearrangement to relocate future heart
Growth of what organ is tremendous at stage of relocating the future heart?
Brain
During relocation of the future heart, what occurs so primitive heart changes position to what will become the definitive thorax?
Folding of the embryo
The endocardial tube is surrounded by what layer?
Epimyocardium–where functioning heart cells will be. (heart surrounded by myocardium wall, then outside will have epimyocardium)
The endocardial tube is initially connected to this structure, which will vanish
dorsal mesocardium
During endocardial heart tube development, you get paired endocardial heart tubes which will eventually fuse to form a single heart tube. What did these initial two tubes start as?
Angiogenetic cell clusters
What are the two ends of the heart tube?
Arterial and venous end
In between the arterial and venous end, what does the heart tube have? What is weird about the structures?
Primitive ventricles and atrium except they are in the incorrect order! (Ventricle on top of atrium). Will need further rearrangement
In the formation of the loop, what happens as result of bending the tube?
The atrium (bottom) will get pushed up and behind
What is the symmetry like in the fetal heart? How is this different from the adult heart?
Everything is symmetrical in the arterial and venous sides, even when the loop is introduced. They are asymmetrical in the adult heart.
After formation of the loop, what is formed?
Primitive canal (AV canal)
What will grow out to divide the canal in half?
Endocardial cushions
A primitive atrium and ventricle develop via the fusion of what?
Endocardial cushions –at this point, it resembles the adult heart more than ever before!
What are the endocardial (AV) cushions, and where do they come from? Function?
Subset of cells in the primordial heart. Major role in proper heart septation
The endocardial cushion gives rise to these two important structures of heart that are critical to proper formation of a 4-chambered heart
heart’s valves and septa
The endocardial cushions consists of these two:
dorsal and ventral