Interatrial septum development Flashcards
1
Q
1st
A
Formane primum narrows as septum primum grows toward endocardial cusion
2
Q
2nd
A
Perfomration in septum primum form foramen secondum;
foramen primum disppears
3
Q
3rd
A
Foramen secondum maintains R to L shunt as septum secondum begins to grow.
4
Q
4th
A
Septum secondum contains a permanent opening
foramen ovale
5
Q
5th
A
Foramen secundum enlarges and upper part of septum primum degenerates
6
Q
6th
A
Remaining portion of septum primum forms valve of foramen ovale.
7
Q
Atrial septum formation
A
Septum secundum and septum primum fuse
8
Q
How does foramen ovale close
A
Soon after birth, due to high LA pressure
