The Right Atrium

• • The right atrium receives oxygen poor blood from the systemic and coronary circuits by the superior vena cava, inferior vena cava, and coronary sinus. This blood flows from the right atrium into the right ventricle.
• The right atrium receives oxygen poor venous blood from systemic circuit by the superior vena cava and the inferior vena cava
• Superior vena cava opens into the posterior, superior portion of right atrium
• From superior vena cava and right atrium, venous blood from

  • head
  • neck
  • upper limbs
  • chest
• Inferior vena cava opens into posterior, inferior portion of right atrium
• From inferior vena cava and right atrium, venous blood from

  • tissues
  • organs
  • from abdominal cavity
  • from pelvic cavity
  • lower limbs
• The veins from the heart itself, called coronary veins, collect blood from the heart wall and deliver it to the coronary sinus
• The pectinate muscles extend along the inner surface of the right auricle and across the anterior wall of the right atrium
• The interatrial septum separates the right and left atria
• From embryonic development until birth, there is an oval opening in septum called formen ovale, which allows blood to flow directly from right atrium into left atrium while lungs are developing
• A small depression called the fossa ovalis remains at the site in the adult heart