Right atrium
Atrium dextrum
CardiovascularOrgansThorax
- What it is
- Thin-walled chamber forming the right border of the heart. It receives the superior and inferior venae cavae and the coronary sinus; its ear-shaped right auricle overlaps the root of the aorta.
- Function
- Collects deoxygenated blood from the body and the heart wall and passes it through the tricuspid valve into the right ventricle.
- Size
- About 4–5 cm across; wall ~2 mm; auricle lined with comb-like pectinate muscles.
- Clinical note
- Contains the sinoatrial node (the natural pacemaker) near the superior vena cava; the fossa ovalis on its septal wall marks the fetal foramen ovale, which stays probe-patent in about 25% of adults.