THE RIGHT AURICLE. 



309 



foramina Thebesii, some of which are recesses closed at the bottom, whilst 

 others are the mouths of minute veins (vence minimse cordis). 



The left and posterior side of the auricle is formed by the septum auricu- 



Fig. 232. THE RIGHT Fig. 232. 



AURICLE AND VEN- 

 TRICLE OPENED AND A 

 PART OF THEIR RlGHT 



AND ANTERIOR WALLS 



REMOVED SO AS TO SHOW 

 THEIR INTERIOR. | 



1, the superior vena 

 cava ; 2, the inferior vena 

 cava at the place where it 

 passes through the dia- 

 phragm, and below the 

 hepatic veins ; 2', the 

 hepatic veins cut short ; 3, 

 placed upon the tubercle 

 of Lower within the cavity 

 of the right auricle ; 3', 

 placed in the fossa oval is, 

 below which is the Eusta- 

 chian valve ; 3", is placed 

 close to the aperture of 

 the great coronary vein 

 and the valve of Thebe- 

 sius ; +, +, placed in 

 the auriculo - ventricular 

 groove, where a narrow 

 portion of the adjacent 

 walls of the auricle and 

 ventricle has been pre- 

 served ; 4, 4, the cavity 

 of the right ventricle on 

 the right side of the sep- 

 tum, the upper figure is 

 immediately below the 

 semilunar valves ; 4', 

 large right columna car- 

 nea ; 5, the anterior ; 5', 



the posterior, and 5", the left or septal segment of the tricuspid valve ; 6, placed in the 

 interior of the pulmonary artery, a part of the interior wall of that vessel having been 

 removed, and a narrow portion of it preserved at its commencement where the semilunar 

 valves are attached. The valves are represented as in a half-closed position ; two of the 

 segments are seen foreshortened, the third sideways ; 7, concavity of the aortic arch close 

 to the cord of the ductus arteriosus ; 8, ascending part or sinus of the arch covered at 

 its commencement by the auricular appendix and pulmonary artery ; 9, placed between 

 the innominate and left common carotid arteries; 10, appendix of the left auricle; 

 11, 11, the outside of the left ventricle, the lower figure near the apex. 



laruvi, a partition which separates it from the left auricle, At the lower 

 part of this septum, and just above the orifice of the inferior vena cava, 

 is situated an oval depression named fossa or fovea ovalis, which is the 

 vestige of the foramen ovale of the foetal heart (vestigium for aminis ovalis), 

 and indicates the original place of communication between the two auricles. 

 It is bounded above and at the sides by a prominent border, which is 

 deficient below, the annulus ovalis or isthmus Vieussenii. Continuous 

 with the anterior inferior extremity of the annulus ovalis is a crescentic 

 fold of endocardium, the Eustachian valve, springing from the anterior 



