Cardiovascular Development Flashcards
embryonic vascular systems
umbilical arteries and veins (placental)
vitelline arteries and veins
intraembryonic circulation with the cardinal system of veins
three sequential systems of vein development
cardinal
subcardinal
supracardinal
common cardinal veins
anterior cardinal - brachiocephalic vein, superior vena cava
posterior cardinal - pelvic and leg veins
subcardinal system
becomes the middle IVC, renal, and gonadal veins
supracardinal system
appears last
develops into azygous system and lower IVC
vitelline system
forms intrahepatic inferior vena cava
hepatic veins
hepatic portal system
components of the embryonic heart tube
endocardial tube
cardiac jelly
myocardial mantle
development of the embryonic heart tube
starts out as left and right tubes that quickly fuse
the interior is shaped into a single sequence of chambers - sinus venosus, atrium, ventricle, bulbus cordis, truncus arteriosus
partitioning of the heart tube
heart bends to the right in the middle of the ventricle, forming two ventricles in sequence
they are separated by a short and incomplete interventricular septum
blood flow is from the atrium to the left ventricle to the right ventricle
dorsal mesocardium
a mesentary that surroudns the embryonic heart
transverse pericardial sinus
a passage between the arteries and veins that forms once dorsal mesocardium breaks down
endocardial cushions
dorsal and ventral structures that partition the A-V canal into left and right sides
development of the IV septum
begins to grow from the floor of the ventricles toward the fused endocardial cushions
septum primum
the primary septum that divides the atrium by growing down toward the endocardial cushions
forms the foramen primum
septum secundum
forms the foramen secundum, which forms the framen ovale with the foramen primum
When does the ventricular division become complete?
when the spiral septum, which partitions into the truncus arteriosus, fuses with the IV septum and the endocardial cushions
What happens to the sinus venosus?
becomes the smooth part of the right atrium and the cornoary sinus
What happens to the bulbus cordis?
becomes the smooth, outflow part of both ventricles, the conus arteriosus and aortic vestibule
ductus arteriosus
a second fetal shunt between the pulmonary and systemic circulations
connects the pulmonary trunk to the aortic arch
there is little pulmonary blood flow until the first breath, when the vascular beds in the lung open with the first breath
becomes the ligamentum arteriosum a few weeks after birth
ductus venosus
a fetal liver bypass
changes at birth triggered by first breath
blood flows to lungs
left atrial pressure increases and closes the foramen ovale
oxygenated blood in the umbilical arteries causes smooth muscles to contract
umbilical veins collapse from lack of blood
ductus venosus becomes the fibrous ligamentum venosum
increased blood flow in left ventricle increases pressure int he aortic arch, decreasing blood flow through ductus arteriosus, allowing it to become the ligamentum arteriosum
Tetralogy of Fallot
faulty spiral septum leading to:
pulmonary stenosis
IV septal defect
overriding aorta
right ventricular hypertrophy
persistent truncus arteriosus
Complete communication between ascending aorta and aortic trunk
big time shunting of the blood to the pulmonary trunk
too much blood comes back to the heart
congestive heart failure develops
transposition of the great arteries
spiral structure didn’t develop
blood flow to the heart is affected
huge interventricular septal defects
need to do surgery for the defect
