@andrewmathias8 re-suggested here. 
Recapping the previous addendums:
Osmosis (https://www.osmosis.org/answers/interatrial-septum):
- āThe interatrial septum forms during the first weeks of fetal developmentā¦ā
Wiki (Interatrial septum - Wikipedia):
- āThe interatrial septum forms during the first and second months of fetal development.ā
I believe, if Iām on the right track, that there is some nuance thatās being lost in the card and might could represent an opportunity for some additional clarity.
As I (currently) have it:
- The interatrial septum itself forms during fetal development.
- The primum and segundum do indeed fuse after birth, though this leads to completion/closure of the atrial septum rather than its formation.
This might admittedly be a relatively minor point, but I wonder if the card couldnāt benefit from some clarity to refine some of that nuance (FWIW this card was brought up in a Reddit post as being the source of some confusion for a number of users, which is what led to my initially digging into this and hoping to find some refinement for the card).
Perhaps something akin to:
- During fetal development, the septum secundum and septum primum fuse to close the {{c1::atrial septum}}
(ācloseā rather than āformā seems like it might be more appropriate here?).
Possible Iām overlooking something, of course, but wanted to follow up out of earnestness. Let me know what you think.
This is a fabulous explanation, I think we should add a condensed version of it to the Extra
Thank you.
I canāt find the original Reddit post that led to this rabbit hole, but the core issue at hand was folks trying to differentiate formation of the septum and closure, which led to confusion as to how to differentiate an atrial septal defect from a patent foramen ovale.
Part of this being that formation of the interatrial septum begins in fetal development (and completes after birth), whereas closure (or lack thereof)/patent foramen ovale would occur postnatally.
Thanks @Brian_BH!
I see where the confusion is coming from here, but ultimately the interatrial septum is just the wall between the atria and it is not fully āformedā until the fusion occurs. I think this is semantics and FA24 says āseptum secundum and septum primum fuse during infancy/early childhood, forming the atrial septumā so I am fine with leaving as is.
Yeah, the wording is tricky. I supported this change originally, but on second thought, I think change āformā to ācloseā could lend itself to the user thinking the correct answer should be {{c1::foramen ovale}}, so Iām unsure now
@anking-maintainers so what are we ultimately doing with this
I recommend changing to āā¦fuse to complete the formation of theā¦ā