develop
Paired endocardial heart tubes develop before the end of the
3rd week and begin to fuse, thus forming the primitive heart.
Circulation of blood flow begins through the heart by the end of week
three as the heart begins to beat.
bulbous cordis becomes
right ventricle
Outflow tracts
Primitive ventricle becomes
left ventricle
Truncus arteriosus becomes
Great vessels
primitive atrium becomes
left and right atrium
The cardinal veins return blood from the
embryo, and the vitelline veins return blood from the yolk sac.
The umbilical veins return
oxygenated blood from the placenta.
Two dorsal aortas fuse in the caudal half of the embryo to form a
single dorsal aorta
As the primitive heart tube develops it begins to fold and twist on itself to form a more
traditional
4-chambered heart shape.
sinus venosus becomes the
, conduction system and gives way to the visceral pericardium.
What is the first structure to develop in fetal echo?
Endocardial this grows in the atrioventricular region of the heart. This endocardial cushion will
grow and develop the heart into right and left canals.
The atrioventricular valves are derived primarily from the
internal layer of the muscular ventricular wall.
The gap between the septum primum and the endocardial cushion is known as the
ostium primum
Another piece of septum begins to develop from the dorsal atrial wall, this is known as
the
septum secundum.
The septum also does not fully meet the endocardial cushion this gap is known as
the
ostium secundum
septum primum and septum secundum meet, there is a very important communication
between the left and right side of the atriums known as the
foramen ovale.
The interventricular septum divides the
right ventricle and the left ventricle.
Rest of the ventricular myocardium becomes the
purkinje fibers
After the oxygenated blood
travels to the umbilical vein, it moves backs towards the
Heart
fetal shunts: ductus arteriosus
allows oxygenated blood in the umbilical vein to bypass the liver and is essential for normal fetal
circulation.
ductus venosus, and sends the oxygenated blood to the