BYPASS VESTIGE. “Foramen ovale → fossa ovalis. This bypass, essentially an oval-shaped hole in the septum dividing the right and left atria, normally closes when the pressure head in the systemic (left) half of the mammalian circulation exceeds that of the pulmonary division, pressing a flap of tissue to close the hole. The tissues soon fuse and all that remains is an oval-shaped depression. However, up to 30% of adult humans retain a patent foramen ovale (PFO, or atrial septal defect.”
https://evolution-outreach.springeropen.com/articles/10.1186/s12052-014-0012-5
linkedin post 2022-06-29 05:12:48
Nigel Fleming
September 21, 2022