Heart Development Flashcards
What are the 3 paired veins of the early embryo?
1) vitelline veins (yolk sac)
2) umbilical veins (from mom)
3) cardinal veins (early veins of embryo heart)
What does primordial myocardium formed from?
splanchnic mesoderm surrounding the percardial coelom
What are the 3 layers of the endocardial tubes?
1) epicardium/ visceral pericardium
2) cardiac jelly (forms AV valves)
3) myocardium is in between
Describe the events that involve endocardial cushioning
At the end of 4th week, endocardial cushioning is formed from dorsal and ventral walls of the AV canal. The cushions fuse and separates the AV canal into left and right AV canals
What is septum primum?
the first wall that grows inferiorly, divides primitive atrium into right and left
What descends to close the opening between the primitive atria? What is that opening called?
septum primum, the opening is foramen primum
What is foramen secundum?
bypass for the lungs that is developed in the septum primum, before the closure of foramen primum
What becomes a flap-valve for foramen ovale?
septum secundum
What did the coronary sinus derived from?
left horn of sinus venosus
What did the posterior wall of the right atrium (sinus venarum) derived from?
right horn of sinus venosus
What does the primitive atrium form in the adult heart?
rough anterior wall of the adult right atrium (pectinate muscles)
What forms the smooth wall of the left atrium?
primordal pulmonary vein
What becomes the left auricle?
primordal left atrium
What are the truncal and bulbar ridges derived from?
mesenchymal cells from neural crest within truncus arteriosus and bulbus cordis
What do the ridges fuse to become?
they turn 180 degrees and fuse to form the aorticopulmonary septum
