The right atrium is larger than the left, but its walls are somewhat thinner, measuring about 2 mm.; its cavity is capable of containing about 57 c.c. It consists of two parts: a principal cavity, or sinus venarum,situated posteriorly, and an anterior, smaller portion, the auricula.
Its interior presents the following parts for examination:
This definition incorporates text from a public domain edition of Gray's Anatomy (20th U.S. edition of Gray's Anatomy of the Human Body, published in 1918 – from http://www.bartleby.com/107/).
- Openings : Superior vena cava, Inferior vena cava, Coronary sinus, Foramina venarum minimarum, Atrioventricular
- Valves : Valve of the inferior vena cava, Valve of the coronary sinus
- Fossa ovalis. Limbus fossæ ovalis, Intervenous tubercle, Musculi pectinati, Crista terminalis