posterior part (right atrium, anatomy)

Last reviewed 01/2018

The posterior part of the right atrium is termed the sinus venarum; also, it includes most of the lateral wall of the chamber. It has a relatively smooth surface compared to the anterior part. The posterior and anterior walls merge at the crista terminalis.

The posterior wall forms the majority of the interatrial septum. It is drained into by the:

  • superior vena cava at its superiorly-sited orifice
  • inferior vena cava at its inferiorly-sited orifice
  • coronary sinus orifice anteroinferior to inferior vena caval orifice
  • foramina venarum minimae
  • anterior cardiac veins
  • right marginal vein - only occasionally