| Fetal Heart | Primitive Heart Tube |
|---|---|
| Smooth part of RA | R horn of sinus venosus |
| Coronary sinus | L horn of sinus venosus |
| R, L auricle | Primitive atrium |
| Smooth part of LA | Primitive pulmonary vein |
| Membranous IV septum | Meet at perimembranous area - 1. L conotruncal ridges |
https://www.youtube.com/watch?v=a0qyagIgBPw
