Expansion
Crista terminalis, pectinate muscles, fossa ovalis and the openings of the venae cavae and coronary sinus
Expansion
- Crista terminalis - the muscular ridge marked externally by the sulcus terminalis
- Pectinate muscles - anterior rough part, derived from the primitive atrium
- Sinus venarum - posterior smooth part, derived from the sinus venosus
- Openings - superior vena cava, inferior vena cava, coronary sinus
- Fossa ovalis - the remnant of the foramen ovale, on the interatrial septum
- Triangle of Koch - bounded by the tendon of Todaro, the septal tricuspid cusp and the coronary sinus, containing the atrioventricular node
The sinoatrial node sits at the top of the crista terminalis, so this single ridge carries both the developmental story and the location of the pacemaker.