532 



RIGHT AURICLE. 



Openings 



Superior cava, 

 Inferior cava, 

 Coronary vein, 

 Foramina Thebesii, 

 Auriculo-ventricular opening. 



Fig. 162.* 



* The anatomy of the heart. 1. The right auricle. 2. The entrance of the 

 superior vena cava 3. The entrance of the inferior cava. 4. The opening 

 of the coronary vein, half closed by the coronary valve. 5. The Eustachian 

 valve. 6. The fossa ovalis, surrounded by the annulus ovalis. /. The tuber- 

 culum Loweri. 8. The musculi pectinati in the appendix auriculae. 9. The 

 auriculo-ventricular opening. 10. The cavity of the right ventricle. 11. The 

 tricuspid valve, attached by the chordae tendineae to the carneae columnae (12). 

 13. The pulmonary artery, guarded at its commencement by three semilunar 

 valves. 14. The right pulmonary artery, passing beneath the arch and be- 

 hind the ascending aorta. 15. The left pulmonary artery, crossing in front 

 of the descending aorta. * The remains of the ductus ar'teriosus, acting as a 

 ligament between the pulmonary artery and arch of the aorta. The arrows 

 mark the course of the venous blood through the right side of the heart. 

 Entering the auricle by the superior and inferior cavae, it passes through the 

 iiuriculo-ventricular opening into the ventricle, and thence through the pul- 

 monary artery to the lungs. 16. The left auricle. 17. The openings of the 

 tour pulmonary veins. 18. The auriculo-ventricular opening. 1Q. The left 

 ventricle. 20. The mitral valve, attached by its chordae tendinese to two large 

 columnae carneae, which project from the walls of the ventricle. 21. The 

 commencement and course of the ascending aorta behind the pulmonary 

 artery, marked by an arrow. The entrance of the vessel is guarded by three 

 seniilunar valves. 22. The arch of the aorta. The comparative thickness of 

 the two ventricles is shown in the diagram. The course of the pure blood 

 through the left side of the heart is marked by arrows. The blood is brought 

 from the lungs by the four pulmonary veins into the left auricle, and passes 

 through the auriculo-ventricular opening into the left ventricle, whence it is 

 conveyed by the aorta to every part of the body. 



